Acrylic compositions including a hindered amine light stabilizer and methods of making and using the same

ABSTRACT

Acrylic compositions comprising a hindered amine light stabilizer are described herein. The acrylic composition may be in the form of a fiber, thread, yarn, and/or fabric. Also described herein are methods of making and using the acrylic compositions and articles comprising an acrylic composition as described herein.

RELATED APPLICATION INFORMATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/547,497, filed Aug. 18, 2017, the disclosure ofwhich is incorporated herein by reference in its entirety.

FIELD

The present invention relates to acrylic compositions comprising ahindered amine light stabilizer (HALS) along with methods of making andusing the same.

BACKGROUND

Acrylic fibers are ideally suited for use in many outdoor textileapplications. Fabrics made from acrylic fibers are highly UV-resistantand can be solution-dyed to provide excellent color stability. Theseproperties create textile goods optimized for many applications inoutdoor environments such as shade structures, awnings, marine coversand outdoor furniture.

In contrast to other fibers and fabrics made from materials such aspolypropylene, polyethylene, polyester, nylon and polyvinylchloride,fibers and fabrics made from acrylics are known to be the mostweatherable even though formulated without UV light stabilizers.

SUMMARY

A first aspect of the present invention is directed to an acryliccomposition comprising: an acrylonitrile polymer having acrylonitrileunits present in an amount of at least 85% by weight of theacrylonitrile polymer; and a hindered amine light stabilizer. In someembodiments, the acrylonitrile polymer is a polyacrylonitrilehomopolymer.

Another aspect of the present invention is directed to a method ofpreparing an acrylic fiber, the method comprising: adding a hinderedamine light stabilizer to an acrylonitrile polymer to provide astabilized acrylic composition; and forming an acrylic fiber from thestabilized acrylic composition, thereby preparing the acrylic fiber. Insome embodiments, forming the acrylic fiber comprises spinning and/orextruding the stabilized acrylic composition to prepare the acrylicfiber.

A further aspect of the present invention is directed to an articlecomprising an acrylic composition of the present invention and/or anacrylic fiber prepared according to a method of the present invention.In some embodiments, the article is a fabric (e.g., an outdoor fabricand/or an automotive interior fabric), shade structure, awning, marinecover, sail (e.g., boat sail), furniture item (e.g., chair, couch,outdoor furniture item, etc.), boat, car, etc.

It is noted that aspects of the invention described with respect to oneembodiment, may be incorporated in a different embodiment although notspecifically described relative thereto. That is, all embodiments and/orfeatures of any embodiment can be combined in any way and/orcombination. Applicant reserves the right to change any originally filedclaim and/or file any new claim accordingly, including the right to beable to amend any originally filed claim to depend from and/orincorporate any feature of any other claim or claims although notoriginally claimed in that manner. These and other objects and/oraspects of the present invention are explained in detail in thespecification set forth below. Further features, advantages and detailsof the present invention will be appreciated by those of ordinary skillin the art from a reading of the figures and the detailed description ofthe preferred embodiments that follow, such description being merelyillustrative of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows chemical structures of acrylonitrile polymers that may bepresent in an acrylic composition and/or used to prepare an acryliccomposition according to example embodiments of the present invention.

FIG. 2 is a schematic diagram overview of an acrylic process accordingto example embodiments of the present invention.

FIG. 3 is a schematic diagram of a wet spinning process according toexample embodiments of the present invention.

FIG. 4 is a schematic diagram of a dry spinning process according toexample embodiments of the present invention.

FIG. 5A is a schematic diagram of part of a system for adding a hinderedamine light stabilizer to an acrylonitrile polymer showing a schematicof a tote or master line used to contain and/or transport a hinderedamine light stabilizer according to example embodiments of the presentinvention.

FIG. 5B is a schematic diagram of part of a system that may be used withthe system of FIG. 5A to add a hindered amine light stabilizer to anacrylonitrile polymer according to example embodiments of the presentinvention.

FIG. 6 is a schematic diagram of a system for adding a hindered aminelight stabilizer to an acrylonitrile polymer during preparation of adope according to example embodiments of the present invention.

FIG. 7 is a graph showing lab scale ecru sample yarn break strengthretention after AATCC 169 Option 3 testing.

FIG. 8 is a graph showing lab scale ecru sample yarn elongationretention after AATCC 169 Option 3 testing.

FIG. 9 is a graph showing lab scale pigmented sample yarn break strengthretention after AATCC 169 Option 3 testing.

FIG. 10 is a graph showing lab scale pigmented sample yarn elongationretention after AATCC 169 Option 3 testing.

FIG. 11 is a graph showing the lab scale ecru sample fabric CIE Delta Evalues after AATCC 169 Option 3 testing.

FIG. 12 a graph showing the lab scale pigmented sample fabric CIE DeltaE values after AATCC 169 Option 3 testing.

FIG. 13 is a graph showing the lab scale ecru sample fabric CIE Delta Evalues after outdoor exposure in South Carolina.

FIG. 14 is a graph showing the lab scale ecru sample fabric CIE Delta Evalues after outdoor exposure in Arizona.

FIG. 15 is a graph showing the production scale ecru sample plain weavefabric 75 epi×35 ppi CIE Delta E values after AATCC 169 Option 3testing.

FIG. 16 is a graph showing the production scale ecru sample plain weavefabric 68 epi×30 ppi CIE Delta E values after AATCC 169 Option 3testing.

FIG. 17 is a graph showing the production scale ecru sample plain weavefabric 75 epi×35 ppi CIE Delta E values after outdoor exposure in SouthCarolina.

FIG. 18 is a graph showing the production scale ecru sample plain weavefabric 68 epi×30 ppi CIE Delta E values after outdoor exposure in SouthCarolina.

FIG. 19 is a graph showing the production scale ecru sample plain weavefabric 75 epi×35 ppi CIE Delta E values after outdoor exposure inArizona.

FIG. 20 is a graph showing the production scale ecru sample plain weavefabric 68 epi×30 ppi CIE Delta E values after outdoor exposure inArizona.

FIG. 21 is a graph of the production scale ecru sample yarn breakstrength retention after AATCC 169 Option 3 testing.

FIG. 22 is a graph of the production scale ecru sample yarn elongationretention after AATCC 169 Option 3 testing.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The present invention is now described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe scope of the invention to those skilled in the art.

The terminology used in the description of the invention herein is forthe purpose of describing particular embodiments only and is notintended to be limiting of the invention. As used in the description ofthe invention and the appended claims, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the present applicationand relevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein. The terminology used inthe description of the invention herein is for the purpose of describingparticular embodiments only and is not intended to be limiting of theinvention. All publications, patent applications, patents and otherreferences mentioned herein are incorporated by reference in theirentirety. In case of a conflict in terminology, the presentspecification is controlling.

Also as used herein, “and/or” refers to and encompasses any and allpossible combinations of one or more of the associated listed items, aswell as the lack of combinations when interpreted in the alternative(“or”).

Unless the context indicates otherwise, it is specifically intended thatthe various features of the invention described herein can be used inany combination. Moreover, the present invention also contemplates thatin some embodiments of the invention, any feature or combination offeatures set forth herein can be excluded or omitted. To illustrate, ifthe specification states that a complex comprises components A, B and C,it is specifically intended that any of A, B or C, or a combinationthereof, can be omitted and disclaimed.

As used herein, the transitional phrase “consisting essentially of” (andgrammatical variants) is to be interpreted as encompassing the recitedmaterials or steps “and those that do not materially affect the basicand novel characteristic(s)” of the claimed invention. See, In re Herz,537 F.2d 549, 551-52, 190 U.S.P.Q. 461, 463 (CCPA 1976) (emphasis in theoriginal); see also MPEP § 2111.03. Thus, the term “consistingessentially of” as used herein should not be interpreted as equivalentto “comprising.”

The term “about,” as used herein when referring to a measurable valuesuch as an amount or concentration and the like, is meant to encompassvariations of ±10%, ±5%, ±1%, ±0.5%, or even ±0.1% of the specifiedvalue as well as the specified value. For example, “about X” where X isthe measurable value, is meant to include X as well as variations of±10%, ±5%, ±1%, ±0.5%, or even ±0.1% of X. A range provided herein for ameasureable value may include any other range and/or individual valuetherein.

As used herein, the terms “increase,” “increases,” “increased,”“increasing,” and similar terms indicate an elevation in the specifiedparameter or value of at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%,40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 150%,200%, 300%, 400%, 500% or more.

As used herein, the terms “reduce,” “reduces,” “reduced,” “reduction,”“inhibit,” and similar terms refer to a decrease in the specifiedparameter or value of at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%,40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97%, or100%.

Provided according to embodiments of the present invention are acryliccompositions. An acrylic composition of the present invention comprisesan acrylonitrile polymer and a hindered amine light stabilizer. As usedherein “acrylonitrile polymer” refers to a polymer having acrylonitrileunits present in an amount of at least 85% by weight of theacrylonitrile polymer. In some embodiments, an acrylonitrile polymerincludes about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99%, or 100% acrylonitrile units by weight of theacrylonitrile polymer. In some embodiments, an acrylonitrile polymercomprises acrylonitrile units in an amount of at least 85% to about 100%by weight of the acrylonitrile polymer. An acrylonitrile polymer of thepresent invention does not include polymethyl methacrylate (PMMA). Insome embodiments, an acrylic composition of the present invention doesnot include PMMA.

An acrylic composition of the present invention comprises or is amanufactured fiber in which the fiber-forming substance includes or isan acrylonitrile polymer as defined herein. In some embodiments, theacrylonitrile polymer is the primary fiber-forming substance. Thus, theacrylic composition of the present invention may also be referred to asa polyacrylonitrile composition. An acrylic fiber of the presentinvention is a manufactured fiber in which the fiber-forming substanceincludes or is an acrylonitrile polymer as defined herein and is theextrudate (e.g., solidified, dried, and/or cooled extrudate) from afiber spinning process (e.g., a wet or dry spinning process). An acrylicfiber of the present invention may be in any suitable form, such as, forexample, staple, tow, filament, or monofilament. Typically, an acrylicstaple fiber has a length in a range from about 0.75 inches to about 18inches, and an acrylic filament fiber has any suitable length (e.g.,greater than 18 inches to about 2, 4, 6, 8, 10, 100, 200, 1,000, 10,000,or 20,000, 30,000 yards or infinite length).

An acrylic yarn of the present invention comprises a plurality ofacrylic fibers arranged in any suitable manner. In some embodiments, anacrylic yarn may be a plurality of acrylic fibers arranged so that atleast a portion (e.g., a majority) of the acrylic fibers of theplurality are parallel to each other and the plurality of acrylic fibersmay be twisted. An acrylic yarn of the present invention may be in anysuitable form, such as, for example, a filament yarn (i.e., a yarn madeusing one or more continuous acrylic fiber(s)) or a staple yarn (i.e., ayarn made using two or more staple acrylic fibers). A filament yarn iscomposed of a continuous filament that may be assembled with or withouttwist. Filament yarns composed of a single filament are calledmonofilaments and those of two or more filaments are calledmultifilaments. A spun or stable yarn is composed of staple fibers thatare held together by a binding mechanism. In some embodiments, anacrylic yarn of the present invention comprises about 80%, 85%, 90%,95%, 98%, or 100% acrylic fibers of the present invention based on theweight of the acrylic yarn or the total number of fibers in the yarn. Insome embodiments, one or more properties (e.g., tensile strength, breakstrength, and/or flexibility) of a yarn (e.g., an acrylic yarn of thepresent invention) may be measured with a yarn having a 18/2 Ring SpunCotton Count with 12.25 turns per inch in the singles yarn and 12.4turns per inch in the ply, with the yarn optionally being prepared with2 denier fibers having a 45 mm staple length.

An acrylic fabric of the present invention comprises a plurality ofacrylic fibers and optionally a plurality of acrylic yarns. A nonwovenacrylic fabric of the present invention comprises a plurality of acrylicfibers that are bonded together, such as, e.g., through physicalentanglement of the acrylic fibers, adhesive bonding of the acrylicfibers, melt bonding of the acrylic fibers, solvent bonding of theacrylic fibers, and any combination thereof. A woven acrylic fabric ofthe present invention comprises a plurality of acrylic yarns that areinterlaced and/or intermeshed. In some embodiments, an acrylic fabricmay be woven in the form of a plain weave, twill weave, leno weave,dobby weave, jacquard weave, and/or satin weave. In some embodiments, anacrylic fabric may be woven in the form of a plain weave. In someembodiments, an acrylic fabric of the present invention comprises about80%, 85%, 90%, 95%, 98%, or 100% acrylic fibers and/or yarns of thepresent invention based on the weight of the fabric or the total numberof fibers and/or yarns in the fabric. In some embodiments, one or moreproperties (e.g., CIE Delta E and/or Gray Scale value) of a fabric(e.g., an acrylic fabric of the present invention) may be measured witha plain weave 75 epi×35 ppi fabric and/or a plain weave 68 epi×30 ppifabric, with the fabric optionally being prepared with a yarn having a18/2 Ring Spun Cotton Count with 12.25 turns per inch in the singlesyarn and 12.4 turns per inch in the ply, with the yarn optionally beingprepared with 2 denier fibers having a 45 mm staple length.

Example acrylonitrile polymers include, but are not limited to,polyacrylonitrile (PAN), poly(acrylonitrile-co-vinyl acetate)(P(AN-VA)), poly(acrylonitrile-co-methyl acrylate) (P(AN-MA)),poly(acrylonitrile-co-vinyl chloride) (PAN-VC),poly(acrylonitrile-co-vinylidene chloride, and/orpoly(acrylonitrile-co-methyl methacrylate). Some example acrylonitrilepolymer structures are shown in FIG. 1, where m may be 0 to 0.15 and nmay be 0.85-1. In some embodiments, the acrylonitrile polymer is apolyacrylonitrile homopolymer (i.e., PAN). In some embodiments, theacrylonitrile polymer is a polyacrylonitrile copolymer (e.g., P(AN-VA),P(AN-MA), PAN-VC, etc.). In some embodiments, the acrylonitrile polymeris selected from poly(acrylonitrile-co-vinyl acetate),poly(acrylonitrile-co-methyl acrylate), and/orpoly(acrylonitrile-co-methyl methacrylate). In some embodiments, theacrylonitrile polymer is poly(acrylonitrile-co-vinyl acetate).

In some embodiments, the acrylonitrile polymer comprises one or more(e.g., 1, 2, 3, 4, 5, or more) comonomer unit(s) (e.g., a neutral and/oracid comonomer unit). A comonomer may be present in an acrylonitrilepolymer in an amount of about 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%,8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% by weight of the acrylonitrilepolymer. In some embodiments, an acrylonitrile polymer comprisescomonomer units in an amount of about 0.1% to about 15% by weight of theacrylonitrile polymer. Example comonomer units include, but are notlimited to, vinyl acetate, vinyl chloride, vinylidene chloride, styrene,methyl methacrylate, vinyl acetate, methyl acrylate, sodium styrenesulfonate, sodium methallyl sulfonate, sodium sulfophenyl methallyl,ether, and/or itaconic acid. As those skilled in the art willunderstand, an acrylonitrile polymer may be obtained by polymerizing anacrylonitrile monomer, optionally in the presence of one or morecomonomers. In some embodiments, an acrylonitrile polymer that may bepresent in and/or used to prepare an acrylic composition of the presentinvention may comprise acrylonitrile units in an amount of about 90% toabout 94% by weight of the acrylonitrile polymer and comonomer units inan amount of about 6% to about 10% by weight of the acrylonitrilepolymer. The comonomer units may comprise neutral comonomer units in anamount of about 6% to about 9% by weight of the acrylonitrile polymerand acid comonomer units in an amount of about 0% to about 1% by weightof the acrylonitrile polymer. In some embodiments, an acrylonitrilepolymer that may be present in and/or used to prepare an acryliccomposition of the present invention may have a composition as providedin Table 1.

TABLE 1 Composition of example acrylonitrile polymers. AcrylonitrileNeutral Comonomer Acid Comonomer 90-94% 6-9% of methyl acrylate, 0-1% ofsodium styrene acrylonitrile vinyl acetate, and/or sulfonate, sodiummethallyl methyl methacrylate sulfonate, sodium sulfophenyl methallylether, and/or itaconic acid

An acrylic composition of the present invention may comprise one or more(e.g., 1, 2, 3, 4, 5, or more) acrylonitrile polymer(s). In someembodiments, the acrylic composition may comprise a blend of apolyacrylonitrile homopolymer and at least one polyacrylonitrilecopolymer. In some embodiments, the acrylic composition may comprise ablend of at least two different polyacrylonitrile copolymers. A blend oftwo or more acrylonitrile polymers may comprise the acrylonitrilepolymers in any suitable amount, such as e.g., about 0.1%, 0.5%, 1%, 5%,10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%,80%, 85%, 90%, 95%, 98%, 99%, or 99.5% based on the total amount of allacrylonitrile polymers present in the acrylic composition.

An acrylonitrile polymer may have any suitable molecular weight. In someembodiments, an acrylonitrile polymer may have a molecular weight in arange from about 40,000 or 90,000 g/mol to about 170,000 or 200,000g/mol. In some embodiments, an acrylonitrile polymer may have amolecular weight of about 40,000, 50,000, 60,000, 70,000, 80,000,90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000,170,000, 180,000, 190,000, or 200,000 g/mol.

A “hindered amine light stabilizer” as used herein refers to a compoundor polymer comprising a substituted piperidinyl group. In someembodiments, the substituted piperidinyl group may comprise 1, 2, 3, 4,5, 6, 7, 8, or more substituents, such as, e.g., an alkyl, alkenyl, oralkoxy group. In some embodiments, the substituted piperidinyl groupcomprises 1 or 2 substituents (e.g., a C1-C20 alkyl or C1-C20 alkenylgroup) at the 2- and/or 6-position of the piperidine ring. In someembodiments, the substituted piperidinyl group is a2,2,6,6-tetraalkylpiperidinyl group (e.g., a2,2,6,6-tetramethylpiperidinyl group). In some embodiments, thesubstituted piperidinyl group comprises hydrogen, an alkyl group or analkoxy group at the 1-position of the piperidine ring. In someembodiments, a hindered amine light stabilizer comprises an amine groupthat acts through and/or participates in a regenerative free radicalscavenging mechanism.

One or more (e.g., 1, 2, 3, 4, 5, or more) substituted piperidinylgroup(s) may be present in a hindered amine light stabilizer. In someembodiments, the hindered amine light stabilizer is a polymer andcomprises one or more (e.g., 1, 2, 3, 4, 5, or more) substitutedpiperidinyl group(s) per repeating unit of the hindered amine lightstabilizer. In some embodiments, an acrylic composition of the presentinvention may comprise a hindered amine light stabilizer that comprisesone or more (e.g., 1, 2, 3, 4, or more) 2,2,6,6-tetraalkylpiperidinylgroup(s) in the hindered amine light stabilizer. In some embodiments,the hindered amine light stabilizer may be a polymeric or oligomerichindered amine light stabilizer, and may comprise one or more (e.g., 1,2, 3, 4, or more) 2,2,6,6-tetraalkylpiperidinyl group(s) per repeatingunit of the hindered amine light stabilizer.

A hindered amine light stabilizer may be present in an acryliccomposition of the present invention in any suitable amount. In someembodiments, a hindered amine light stabilizer is present in an acryliccomposition of the present invention in an amount in a range of about0.01%, 0.5%, or 1% to about 2%, 3% or 10% by weight of the acryliccomposition (e.g., acrylic fiber). In some embodiments, a hindered aminelight stabilizer is present in an acrylic composition of the presentinvention in an amount of about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%,0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%,0.8%, 0.9%, 1%, 1.25%, 1.5%, 1.75%, 2%, 2.25%, 2.5%, 2.75%, 3%, 3.25%,3.5%, 3.75%, 4%, 4.25%, 4.5%, 4.75%, 5%, 5.25%, 5.5%, 5.75%, 6%, 6.25%,6.5%, 6.75%, 7%, 7.25%, 7.5%, 7.75%, 8%, 8.25%, 8.5%, 8.75%, 9%, 9.25%,9.5%, 9.75%, or 10% by weight of the acrylic composition. In someembodiments, one or more (e.g., 1, 2, 3, 4, 5, or more) differenthindered amine light stabilizer(s) may be present in the acryliccomposition. In some embodiments, a hindered amine light stabilizer mayscavenge, bind, trap, and/or remove one or more free radical(s) presentin the acrylic composition.

Example hindered amine light stabilizers include, but are not limitedto, those under the tradename Tinuvin® commercially available from BASF,such as, e.g., Tinuvin® PA 123, Tinuvin® 371, Tinuvin® 111 and/orTinuvin® 622; those under the tradename Chimassorb® commerciallyavailable from BASF, such as, e.g., Chimassorb® 2020; and/or those underthe tradename Cyasorb® commercially available from Cytec Industries,Inc., such as, e.g., Cyasorb® UV-3529.

A hindered amine light stabilizer may have a pKa in a range from about2, 2.5, 3, 3.5, or 4 to about 5, 5.5, 6, 6.5, 7, 7.5, or 8. In someembodiments, a hindered amine light stabilizer may have a pKa of about2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8. In someembodiments, the hindered amine light stabilizer has a pKa in a rangefrom about 3.5 to about 4.5 or from about 6 to about 7 or 7.5.

A hindered amine light stabilizer may have any suitable molecularweight. In some embodiments, a hindered amine light stabilizer has anumber average molecular weight in a range from about 1000, 2000 or 3000g/mol to about 4000, 5000, 10,000, or 20,000 g/mol. In some embodiments,a hindered amine light stabilizer has a molecular weight in a range fromabout 500 or 700 g/mol to about 1000, 2000, or 4500 g/mol. In someembodiments, a hindered amine light stabilizer has a molecular weight ofabout 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000,or 4500 g/mol. In some embodiments, a hindered amine light stabilizerhas an average molecular weight in a range from about 600 or 700 g/molto about 1000 g/mol or from about 3000 g/mol to about 4000 g/mol and apKa in a range from about 2, 2.5, 3 or 3.5 to about 5, 5.5, 6, 6.5, 7,7.5, or 8.

A hindered amine light stabilizer may be soluble in one or more solvents(e.g., a polar organic solvent). In some embodiments, a hindered aminelight stabilizer may have a lower solubility in water compared to itssolubility in a polar organic solvent, such as, e.g., acetone,N,N-dimethylformamide (DMF), DMAc, acetonitrile, dimethylsulfoxide(DMSO), etc. In some embodiments, a hindered amine light stabilizer mayhave a water solubility at 20° C. of less than about 2%, 1%, 0.1%, or0.01% w/w. In some embodiments, a hindered amine light stabilizer may besoluble in a solvent (e.g., acetone, DMF, acetonitrile, DMSO, toluene,dimethyl acetamide (DMAc), etc.) at 20° C. or room temperature in anamount of about 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%,80%, 85%, 90%, 95%, or 100% w/w.

In some embodiments, the hindered amine light stabilizer has a structurerepresented by Formula (I), Formula (II), Formula (III), or Formula(IV):

wherein:

each X is independently selected from the group consisting of C1-C20alkyl and C1-C20 alkenyl;

L, in each instance, is absent or is independently selected from thegroup consisting of C1-C20 alkyl and C1-C20 alkenyl;

each R¹ is independently selected from the group consisting of hydrogen,C1-C20 alkyl, C1-C20 alkenyl, —O(C1-C20 alkyl), and —O(C1-C20 alkenyl);

each R² is independently selected from the group consisting of hydrogen,C1-C20 alkyl, and C1-C20 alkenyl;

each R³ is independently selected from the group consisting of hydrogen,C1-C20 alkyl, and C1-C20 alkenyl; and

n is an integer selected from 1 to 1,000,000 (e.g., 1 to 100,000; 1 to10,000; 1 to 1,000; 1 to 100; or 1 to 10).

In some embodiments, in a compound of Formula (I), (II), (III), or (IV),R¹ may be —O(C1-C20 alkyl) or —O(C1-C20 alkenyl), and, in someembodiments, R¹ may be —O(C1-C4 alkyl) or —O(C1-C4 alkenyl).

“Alkyl” or “alkyl group,” as used herein, means a straight-chain (i.e.,unbranched), branched, or cyclic hydrocarbon chain that is completelysaturated. In some embodiments, alkyl groups contain 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms(e.g., C1-4, C2-4, C3-4, C1-5, C2-5, C3-5, C1-6, C2-6, C3-6, C2-7, C1-8,C4-8, C4-20, C6-10, C6-20, C8-10, C8-20, etc.). In some embodiments, analkyl group contains 1-8 carbon atoms. In some embodiments, an alkylgroup contains 1-6 carbon atoms. In some embodiments, an alkyl groupcontains 6-20 carbon atoms. In some embodiments, an alkyl group contains2-3 carbon atoms, and in some embodiments, an alkyl group contains 1-4carbon atoms. In some embodiments, the term “alkyl” or “alkyl group”means a straight-chain (i.e., unbranched) or branched hydrocarbon chainthat is completely saturated. In certain embodiments, the term “alkyl”or “alkyl group” refers to a cycloalkyl group, also known as carbocycle.Non-limiting examples of example alkyl groups include methyl, ethyl,propyl, isopropyl, butyl, cyclopropyl and cyclohexyl.

“Alkenyl” or “alkenyl group,” as used herein, refers to a straight-chain(i.e., unbranched), branched, or cyclic hydrocarbon chain that has oneor more double bonds. In certain embodiments, an alkenyl group contains1-20 carbon atoms. In certain embodiments, an alkenyl group contains 1-6carbon atoms. In some embodiments, an alkenyl group contains 6-20 carbonatoms. In still other embodiments, an alkenyl group contains 1-4 carbonatoms, and in some embodiments, an alkenyl group contains 2-3 carbonatoms. In some embodiments, the term “alkenyl” or “alkenyl group” refersto a straight-chain (i.e., unbranched) or branched hydrocarbon chainthat has one or more double bonds. According to some embodiments, theterm alkenyl refers to a straight chain hydrocarbon having two doublebonds, also referred to as “diene.” In other embodiments, the term“alkenyl” or “alkenyl group” refers to a cycloalkenyl group.Non-limiting examples of alkenyl groups include —CH═CH₂, —CH₂CH═CH₂(also referred to as allyl), —CH═CHCH₃, —CH₂CH₂CH═CH₂, —CH₂CH═CHCH₃,—CH═CH₂CH₂CH₃, —CH═CH₂CH═CH₂, and cyclobutenyl.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (I). In some embodiments, in the compound ofFormula (I), L may be absent or a C1-C4 alkyl; X may be a C4-C12 alkyl,C6-C10 alkyl, C4-C12 alkenyl, or C6-C10 alkenyl; each R¹ isindependently a C4-C12 alkyl, C6-C10 alkyl, C4-C12 alkenyl, C6-C10alkenyl, —O(C4-C12 alkyl), —O(C4-C12 alkenyl), —O(C6-C10 alkyl), or—O(C6-C10 alkenyl); and/or each R² is independently a C1-C4 alkyl orC1-C4 alkenyl. In some embodiments, in the compound of Formula (I), Lmay be absent; X may be a C6-C10 alkyl; each R¹ is independently a—O(C6-C10 alkyl); and/or each R² is independently a C1-C4 alkyl. In someembodiments, in the compound of Formula (I), L may be absent; X may be aC8 alkyl; each R¹ is a —O(C8 alkyl); and/or each R² is a methyl group.In some embodiments, in the compound of Formula (I), each L is the same,each R¹ is the same, and/or each R² is the same.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (Ia):

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (II). In some embodiments, in the compound ofFormula (II), each X is independently a C1-C6 alkyl, C1-C4 alkyl, C1-C6alkenyl, or C1-C4 alkenyl; each R² is independently a C1-C4 alkyl orC1-C4 alkenyl; and/or n is 1 to 100 or 1 to 15. In some embodiments, inthe compound of Formula (II), each X is independently a C1-C4 alkyl;each R² is independently a C1-C4 alkyl; and/or n is 1 to 15. In someembodiments, in the compound of Formula (II), each X is a C2 alkyl; eachR² is a methyl group; and/or n is 1 to 15. In some embodiments, in thecompound of Formula (II), each X is the same and/or each R² is the same.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (IIa):

optionally wherein n is 9, 10, 11, 12, 13, or 14.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (III). In some embodiments, in the compound ofFormula (III), X may be a C1-C10 alkyl, C1-C8 alkyl, C1-C10 alkenyl, orC1-C8 alkenyl; each R¹ is independently a C1-C6 alkyl, C1-C4 alkyl,C1-C6 alkenyl, C1-C4 alkenyl, —O(C1-C6 alkyl), —O(C1-C6 alkenyl),—O(C1-C4 alkyl), or —O(C1-C4 alkenyl); each R² is independently a C1-C4alkyl or C1-C4 alkenyl; and/or n is 1 to 10 or 1 to 5. In someembodiments, in the compound of Formula (III), X may be a C1-C8 alkyl;each R¹ is independently a C1-C4 alkyl; each R² is independently a C1-C4alkyl; and/or n is 1 to 5. In some embodiments, in the compound ofFormula (III), X may be a C6 alkyl; each R¹ is a methyl group; each R²is a methyl group; and/or n is 1 to 5. In some embodiments, in thecompound of Formula (III), each R¹ is the same and/or each R² is thesame.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (IIIa):

optionally wherein n is 2, 3, 4, or 5.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (IV). In some embodiments, in the compound ofFormula (IV), X may be a C2-C12 alkyl, C2-C8 alkyl, C2-C12 alkenyl, orC2-C8 alkenyl; each R¹ is independently hydrogen, C1-C4 alkyl, C1-C4alkenyl, —O(C1-C4 alkyl), or —O(C1-C4 alkenyl); each R² is independentlya C1-C4 alkyl or C1-C4 alkenyl; R³ is a C1-C10 alkyl, C1-C8 alkyl,C1-C10 alkenyl, or C1-C8 alkenyl; and/or n is 1 to 100 or 1 to 10. Insome embodiments, in the compound of Formula (IV), X may be a C2-C8alkyl; each R¹ is independently hydrogen or a C1-C4 alkyl; each R² isindependently a C1-C4 alkyl; R³ is a C1-C8 alkyl; and/or n is 1 to 10.In some embodiments, in the compound of Formula (IV), X may be a C6alkyl; each R¹ is hydrogen; each R² is independently a methyl group; R³is a C4 alkyl; and/or n is 1 to 10. In some embodiments, in the compoundof Formula (IV), each R¹ is the same and/or each R² is the same.

In some embodiments, an acrylic composition of the present inventioncomprises a hindered amine light stabilizer having a structurerepresented by Formula (IVa):

optionally wherein n is 2, 3, 4, 5, 6, 7, or 8.

A hindered amine light stabilizer may be distributed and/or incorporatedthroughout an acrylic composition of the present invention. In someembodiments, the hindered amine light stabilizer is distributed and/orincorporated substantially uniformly throughout the acrylic composition.In some embodiments, when the acrylic composition is in the form of afiber, the hindered amine light stabilizer is distributed and/orincorporated substantially uniformly throughout the fiber. In someembodiments, when the acrylic composition is in the form of a fiber, afirst hindered amine light stabilizer may be present at, proximate to,and/or concentrated at or near a surface of the fiber and a secondhindered amine light stabilizer may be distributed substantiallyuniformly throughout the fiber. In some embodiments, the hindered aminelight stabilizer is within the acrylic fiber and/or within the polymermatrix of the acrylic fiber. In some embodiments, the hindered aminelight stabilizer is distributed throughout the polymer matrix of theacrylonitrile polymer.

A hindered amine light stabilizer may or may not be chemically bound toan acrylonitrile polymer present in the acrylic composition. In someembodiments, the hindered amine light stabilizer may be ionically and/orcovalently bound to a portion of the acrylonitrile polymer. In someembodiments, the hindered amine light stabilizer may be associated witha portion of the acrylonitrile polymer through hydrogen bonding, a Vandeer Waals force, and/or a dipole interaction. In some embodiments, ahindered amine light stabilizer may be entrapped and/or encapsulated(partially or entirely) by one or more portions and/or chains of anacrylonitrile polymer in an acrylic composition of the presentinvention. In some embodiments, a hindered amine light stabilizer maynot be chemically reacted and/or bound to the acrylonitrile polymer, butmay physically be partially or entirely entrapped and/or encapsulated bythe acrylonitrile polymer.

An acrylic composition of the present invention may be in any suitableform, such as, e.g., in the form of a fiber, thread, yarn, and/orfabric. In some embodiments, the acrylic composition is an outdoorfabric and/or is a fabric that is suitable for outdoor applications(e.g., shade structures, awnings, marine covers, sails, outdoorfurniture, etc.). In some embodiments, the acrylic composition is afabric such as, e.g., an automotive fabric, which may be an interiorand/or exterior automotive fabric. In some embodiments, an acryliccomposition of the present invention is a fabric comprising an acrylicfiber, thread, and/or yarn. Also provided herein is an article, such as,but not limited to, a shade structure, awning, marine cover, outdoorfurniture item, car, boat, chair, sail, and/or couch, comprising anacrylic composition of the present invention (e.g., a fiber, yarn,thread, and/or fabric).

In some embodiments, one or more (e.g., 1, 2, 3, 4, 5, 6, or more)pigment(s) may be present in the acrylic composition. In someembodiments, an acrylic composition comprises at least 2, 3, 4, or morepigments. In some embodiments, the acrylic composition is solution-dyed.In some embodiments, the acrylic composition is unpigmented (alsoreferred to herein as ecru or natural).

One or more (e.g., 1, 2, 3, 4, 5, or more) additional component(s) oradditive(s) may be present in an acrylic composition of the presentinvention including, but not limited to, a heat stabilizer, catalyst,solvent, and/or impurity (e.g., residual catalyst, residual solvent,etc.). In some embodiments, a heat stabilizer (e.g., an antioxidant) maybe present in an acrylic composition of the present invention in anamount known to those of skill in the art.

The inventors of the present invention discovered that a hindered aminelight stabilizer can be included in an acrylic composition comprising anacrylonitrile polymer (e.g., a polyacrylonitrile homopolymer and/orcopolymer) and may provide improved properties. As described herein, itwas unexpected that improvements could be made (e.g., improvements inweatherability, UV-resistance, color stability, etc.) while maintainingor increasing fiber strength properties (e.g., tensile strength,flexibility, etc.).

An acrylic composition (e.g., fabric) of the present invention may havea UV-resistance that is increased by at least about 10% (e.g., at leastabout 20%, 30%, or more) compared to a comparative composition. In someembodiments, increased UV-resistance may be determined with anunpigmented acrylic composition of the present invention and anunpigmented comparative composition. For example, an unpigmented acryliccomposition of the present invention and an unpigmented comparativecomposition and/or one or more properties thereof may be compared.

“Comparative composition” as used herein collectively refers to acurrent commercial acrylic composition and/or a control composition,each of which may be in the same form as the acrylic composition of thepresent invention that it is being compared to. An example currentcommercial acrylic composition of the same form may be, but is notlimited to, a current commercial acrylic fabric (e.g., a currentcommercial acrylic outdoor fabric) when the acrylic composition of thepresent invention is a fabric. An example control composition of thesame form is when the acrylic composition of the present invention is inthe form of, e.g., a fabric, the control composition is a fabricprepared in the same manner with the same materials except without ahindered amine light stabilizer. Similarly, when the acrylic compositionof the present invention is a fiber or yarn, the control composition isa fiber or yarn, respectively, prepared in the same manner with the samematerials except without a hindered amine light stabilizer. In someembodiments, a comparative composition has a composition as provided inTable 1.

In some embodiments, an acrylic composition (e.g., fabric) of thepresent invention has a color stability that is increased by at leastabout 10% (e.g., at least about 20%, 30%, or more) compared to a currentcommercial acrylic composition of the same form (e.g., a currentcommercial acrylic fabric) and/or a control composition of the same form(e.g., a fabric without a hindered amine light stabilizer). In someembodiments, improvements in color stability may be determined uponvisual comparison with the human eye. In some embodiments, increasedcolor stability may be determined with an unpigmented acryliccomposition of the present invention and/or an unpigmented comparativecomposition, e.g., by comparing the compositions and/or one or moreproperties thereof.

An acrylic composition (e.g., fabric) of the present invention may havereduced or no discoloration (e.g., yellowing or browning) compared to acurrent commercial acrylic composition of the same form (e.g., a currentcommercial acrylic fabric) and/or a control composition of the same form(e.g., a fabric without a hindered amine light stabilizer). In someembodiments, the acrylic composition has a reduction in discoloration ofat least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or morecompared to a comparative composition. In some embodiments,discoloration may be determined with an unpigmented acrylic compositionof the present invention and/or an unpigmented comparative composition.“Discoloration” as used herein, refers to any change in color comparedto the initial (i.e., original) color of the acrylic composition uponformation of the acrylic composition (i.e., at time point 0). In someembodiments, discoloration may appear as a change in the color (e.g., achange to a different shade and/or a color shift) of the acryliccomposition, fading of the color of the acrylic composition, staining ofthe acrylic composition, and/or yellowing or browning of the acryliccomposition (i.e., the appearance of yellow or brown in the acryliccomposition).

In some embodiments, an acrylic composition (e.g., fabric) of thepresent invention may have reduced or no discoloration (e.g., yellowingor browning) after a period of time and/or after exposure to certainconditions compared to the original color of the acrylic composition.When compared to the original color of the acrylic composition, anacrylic composition of the present invention may have no discolorationor a reduction in discoloration of at least about 5%, 10%, 15%, 20%,25%, 30%, 35%, 40%, 45%, 50%, or more after a period of time and/orafter exposure to certain conditions. The amount of discoloration may bedetermined and/or measured at any point in time, such as, e.g., at about1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23, 24 month(s) or year(s) or more after initial formation ofthe acrylic composition. In some embodiments, the amount ofdiscoloration may be determined and/or measured after exposure tocertain conditions, such as, but not limited to, real world outdoorconditions (e.g., in California, Arizona and/or Texas), sun exposure,heat exposure, and/or conditions in accordance with AATCC 169 Option 3(AATCC TM169-2009, “Weather Resistance of Textiles: Xenon Lamp Exposure”Developed in 1987 by AATCC Committee RA64 (editorially revised andreaffirmed 2009)). In some embodiments, discoloration of an acryliccomposition of the present invention is determined and/or measured afterthe acrylic composition is exposed to 880, 1320, or 2200 kJ inaccordance with AATCC 169 Option 3. In some embodiments, the AATCC 169Option 3 test method is performed using a borosilicate/borosilicatefilter with 0.35 W/m² irradiance at 340 nm, 77° C.±3° C. black paneltemperature, 27±3% relative humidity (RH) with continuous lightexposure.

In some embodiments, an acrylic composition of the present (e.g.,fabric) has a weatherability that is increased by at least 5% (e.g.,about 10%, 15%, 20%, 25%, 30%, or more) compared to a current commercialacrylic composition of the same form (e.g., a current commercial acrylicfabric) and/or a control composition of the same form (e.g., a fabricwithout a hindered amine light stabilizer). Weatherability may bemeasured using methods known to those of skill in the art, such as, butnot limited to, artificial simulations of weathering using a xenon arcsuch as, e.g., AATCC 169 Option3 (AATCC TM169-2009, “Weather Resistanceof Textiles: Xenon Lamp Exposure” Developed in 1987 by AATCC CommitteeRA64 (editorially revised and reaffirmed 2009); AATCC Test Method16.3-2014 “Colorfastness to Light: Xenon-Arc”; SAE J2527 “PerformanceBased Standard for Accelerated Exposure of Automotive Exterior MaterialsUsing a Controlled Irradiance Xenon-Arc Apparatus” J2527_200402, Issued:2004 Feb. 11; ISO 105-B04:1994 “Textiles—Tests for colour fastness—PartB04: Colour fastness to artificial weathering: Xenon arc fading lamptest”; ISO 105-B02:2014(en) “Textiles—Tests for colour fastness—PartB02: Colour fastness to artificial light: Xenon arc fading lamp test”;and ASTM G154-16, “Standard Practice for Operating FluorescentUltraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials,”ASTM International, West Conshohocken, Pa., 2016. In some embodiments,weatherability, color stability and/or one or more physical propertiesof an acrylic composition of the present invention may be tested inregard to resistance to acid, rain, salt, pollutant(s), and/orchemical(s) using methods known to those of skill in the art.

The weatherability may be measured and/or determined upon initialformation of the composition and/or at about 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 month(s) oryear(s) or more after initial formation of the composition and/or afterexposure to certain conditions, such as, but not limited to, real worldoutdoor conditions (e.g., in California, Arizona and/or Texas), sunexposure, heat exposure, and/or conditions in accordance with AATCC 169Option 3. In some embodiments, the acrylic composition has aweatherability that is increased by at least 5%, 10%, 15%, or 20% atabout 3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or 12months or 5 or 10 years of outdoor exposure) and/or after exposure to880, 1320, or 2200 kJ in accordance with AATCC 169 Option 3 compared toa comparative composition. In some embodiments, improvements inweatherability of an acrylic composition of the present inventioncompared to a comparative composition may be determined by comparing thetensile strength, break strength, and/or flexibility of thecompositions. In some embodiments, weatherability may be determined withan unpigmented acrylic composition of the present invention and/or anunpigmented comparative composition, e.g., by comparing the compositionsand/or one or more properties thereof.

UV-resistance, color stability, weatherability, and/or discoloration maybe measured and/or determined using methods known to those of skill inthe art. In some embodiments, UV-resistance, color stability,weatherability, and/or discoloration may be measured and/or determinedby measuring and/or determining the difference and/or distance between afirst color (e.g., a first color value) and a second color (e.g., asecond color value). In some embodiments, the difference and/or distancebetween a first color and a second color may be measured and/ordetermined by measuring and/or determining the CIE Delta E and/or GrayScale value. The CIE Delta E values are CIELAB units of color change asdetermined by AATCC 169 Option 3. In some embodiments, the CIE Delta Eand/or Gray Scale value may be determined in accordance with AATCCEvaluation Procedure 6, “Instrumental Color Measurement” and/or AATCCEvaluation Procedure 1, “Gray Scale for Color Change”. The first colorand second color may be from the same composition, but at differentpoints in time and/or after exposure to certain conditions (e.g., samesample tested at different times). In some embodiments, the first colorand second color are the same. In some embodiments, the first color maybe the initial color of the acrylic composition and the second color maybe the color of the acrylic composition after a period of time and/orexposure to certain conditions. In some embodiments, the first color maybe the color of the acrylic composition after a period of time and/orafter exposure to certain conditions and the second color may be thecolor of a comparative composition of the same form after the sameperiod of time and/or after exposure to the same conditions. In someembodiments, a CIE Delta E and/or Gray Scale value may be determinedafter exposure for at least about 7 days to a temperature of about 85°C. to about 100° C. (e.g., about 85° C.) in forced air oven and/or maybe determined in accordance with LP-463LB-13-01, May 4, 2006, “HeatAging of Trim Materials”. In some embodiments, color change and/or a CIEDelta E and/or Gray Scale value may be measured devoid of a pigment(e.g., the acrylic composition is unpigmented), which may allow for anychange in color or value to more easily be observed. In someembodiments, an acrylic composition, when measured devoid of a pigment,exhibits no visually perceptive color change after exposure to about 100kJ of light and/or the acrylic composition, when measured devoid of apigment, has a Gray scale value of 5 after exposure to about 100 kJ oflight.

In some embodiments, an acrylic composition of the present invention mayhave a CIE Delta E value of about 20, 19, 18, 17, 16, 15, 14, 13, 12,11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, or less when measuring the color ofthe acrylic composition after a period of time and/or after exposure tocertain conditions compared to the initial color of the acryliccomposition. In some embodiments, the CIE Delta E is measured at about1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23, 24 month(s) or year(s) or more after initial formation ofthe acrylic composition and/or after exposure to certain conditions,such as, but not limited to, real world outdoor conditions (e.g., inCalifornia, Arizona and/or Texas), sun exposure, heat exposure, and/orconditions in accordance with AATCC 169 Option 3. In some embodiments,an acrylic composition of the present invention (e.g., fabric) has a CIEDelta E value of less than about 3, 2, or 1 at about 3, 6, 9, or 12months or 5 or 10 years (e.g., 3, 6, 9, or 12 months or 5 or 10 years ofoutdoor exposure) and/or after exposure to 880, 1320, or 2200 kJ inaccordance with AATCC 169 Option 3.

In some embodiments, the CIE Delta E of an acrylic composition of thepresent invention (e.g., a fabric) varies (i.e., increases or decreases)by less than about ±70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%,20%, 15%, 10%, or 5% after a period of time and/or after exposure tocertain conditions compared to a prior CIE Delta E value for the acryliccomposition. For example, in some embodiments, the CIE Delta E value atabout 3 months varies by less than about ±70% compared to the CIE DeltaE value at about 6, 9, 12, 18, or 24 months and/or the CIE Delta E valueafter exposure to 880 kJ varies by less than about ±70% compared to theCIE Delta E value after exposure to 2200 kJ in accordance with AATCC 169Option 3. In some embodiments, an acrylic composition of the presentinvention (e.g., fabric) has a CIE Delta E value that varies by lessthan about ±70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%,10%, or 5% at about 3, 6, 9, and/or 12 months and/or 5 and/or 10 years(e.g., 3, 6, 9, or 12 months or 5 or 10 years of outdoor exposure)and/or after exposure to 880, 1320, and/or 2200 kJ in accordance withAATCC 169 Option 3 compared to a prior CIE Delta E value.

In some embodiments, the CIE Delta E of an acrylic composition of thepresent invention (e.g., a fabric) varies by less than about ±70%, 65%,60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5% over a 12month time period during which the acrylic composition is exposed tocertain conditions, such as, but not limited to, real world outdoorconditions (e.g., in California, Arizona and/or Texas), sun exposure,heat exposure, and/or conditions in accordance with AATCC 169 Option 3.The variance over the 12 month time period (e.g., 12 months afterinitial formation of the acrylic composition) may be determined bycomparing the lowest CIE Delta E value and highest CIE Delta E valuemeasured during the 12 month period to determine the percent difference.In some embodiments, the CIE Delta E value increases by less than about±70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5%during the 12 month time period.

In some embodiments, the CIE Delta E of an acrylic composition of thepresent invention (e.g., a fabric) increases by less than about 70%,65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 1%, or0% after a period of time and/or after exposure to certain conditionscompared to a prior CIE Delta E value. For example, in some embodiments,the CIE Delta E value at 3 months increases by less than about 70%compared to the CIE Delta E value at 6, 9, 12, 18, or 24 months and/orthe CIE Delta E value after exposure to 880 kJ increases by less thanabout 70% compared to the CIE Delta E value after exposure to 2200 kJ inaccordance with AATCC 169 Option 3. In some embodiments, an acryliccomposition of the present invention (e.g., fabric) has a CIE Delta Evalue that increases by less than about 70%, 65%, 60%, 55%, 50%, 45%,40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 1%, or 0% at about 3, 6, 9,and/or 12 months and/or 5 and/or 10 years (e.g., 3, 6, 9, or 12 monthsor 5 or 10 years of outdoor exposure) and/or after exposure to 880,1320, and/or 2200 kJ in accordance with AATCC 169 Option 3 compared to aprior CIE Delta E value.

In some embodiments, an increase in UV-resistance, weatherability,and/or color stability and/or a reduction in discoloration is determinedby comparing the CIE Delta E for an acrylic composition of the presentinvention and the CIE Delta E for a comparative composition (e.g., acontrol composition of the same form), wherein the CIE Delta E for eachis measured after a period of time and/or after exposure to certainconditions compared to the initial color of each composition. Anincrease in UV-resistance, weatherability, and/or color stability and/ora reduction in discoloration may be demonstrated by the acryliccomposition having a lower CIE Delta E value than the CIE Delta E valueof the comparative composition, optionally at the same point in timeand/or after exposure to the same conditions. In some embodiments, theacrylic composition may have a CIE Delta E value that is lower by atleast about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%,65%, 70% or more compared to the CIE Delta E value of the comparativecomposition, optionally at the same point in time and/or after exposureto the same conditions.

In some embodiments, an acrylic composition of the present invention mayhave a Gray Scale value of about 2.5, 3, 3.5, 4, 4.5, or 5 whenmeasuring the color of the acrylic composition after a period of timeand/or after exposure to certain conditions compared to the initialcolor of the acrylic composition. In some embodiments, the Gray Scalevalue is measured at about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 month(s) or year(s) or moreafter initial formation of the acrylic composition and/or after exposureto certain conditions, such as, but not limited to, real world outdoorconditions (e.g., in California, Arizona and/or Texas), sun exposure,heat exposure, and/or conditions in accordance with AATCC 169 Option 3.In some embodiments, an acrylic composition of the present invention(e.g., fabric) has a Gray Scale value of about 3.5, 4, 4.5, or 5 atabout 3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or 12months or 5 or 10 years of outdoor exposure) and/or after exposure to880, 1320, or 2200 kJ in accordance with AATCC 169 Option 3.

In some embodiments, the Gray Scale value of an acrylic composition ofthe present invention (e.g., a fabric) varies by ±0, 0.5, 1, 1.5, or 2after a period of time and/or after exposure to certain conditionscompared to the initial color of the acrylic composition. In someembodiments, an acrylic composition of the present invention (e.g.,fabric) has a Gray Scale value that varies by ±0, 0.5, 1, 1.5, or 2 atabout 3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or 12months or 5 or 10 years of outdoor exposure) and/or after exposure to880, 1320, or 2200 kJ in accordance with AATCC 169 Option 3.

In some embodiments, an increase in UV-resistance, weatherability,and/or color stability and/or a reduction in discoloration is determinedby comparing the Gray Scale value for an acrylic composition of thepresent invention and the Gray Scale value for a comparative composition(e.g., a control composition of the same form), wherein the Gray Scalevalue for each is measured after a period of time and/or after exposureto certain conditions compared to the initial color of each composition.An increase in UV-resistance, weatherability, and/or color stabilityand/or a reduction in discoloration may be demonstrated by the acryliccomposition having a higher Gray Scale value than the Gray Scale valueof the comparative composition, optionally at the same point in timeand/or after exposure to the same conditions. In some embodiments, theacrylic composition may have a Gray Scale value that is higher by atleast 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4 compared to the Gray Scale valueof the comparative composition, optionally at the same point in timeand/or after exposure to the same conditions.

As described above, it was surprisingly discovered by the inventors ofthe present invention that not only could color stability and/ordiscoloration of an acrylic composition be improved by including ahindered amine light stabilizer, but also that one or more physicalproperties of the acrylic composition could be retained or improved.Inclusion of an additive may negatively affect one or more physicalproperties of the fiber (e.g., tensile strength, break strength,flexibility, etc.). In contrast, the inventors of the present inventiondiscovered that one or more physical properties such as, e.g., strengthand/or elongation retention, may be greater after exposure to certainconditions (e.g., after exposure to 100, 250, 500, 880, 1320, or 2200 kJin accordance with AATCC 169 Option 3) when a hindered amine lightstabilizer is included in an acrylic composition of the presentinvention compared a control composition without the hindered aminelight stabilizer. In some embodiments of the present invention, no orminimal reduction in fine physical structures and/or properties isobserved. In some embodiments, an acrylic composition of the presentinvention (e.g., fabric) has a strength retention that is increased byat least 5% or 10% (e.g., about 5%, 10%, 15%, 20%, 25%, 30%, or more)compared to a current commercial acrylic composition of the same form(e.g., a current commercial acrylic fabric) and/or a control compositionof the same form (e.g., a fabric without a hindered amine lightstabilizer). Strength retention may be measured in accordance with AATCC169 Option 3.

In some embodiments, an acrylic composition of the present invention(e.g., fabric) has a tensile strength that is increased by at least 5%(e.g., about 10%, 15%, 20%, 25%, 30%, or more) compared to a currentcommercial acrylic composition of the same form (e.g., a currentcommercial acrylic fabric) and/or a control composition of the same form(e.g., a fabric without a hindered amine light stabilizer). Tensilestrength may be measured in accordance with ASTM D2256/D2256M-10(2015),Standard Test Method for Tensile Properties of Yarns by theSingle-Strand Method, ASTM International, West Conshohocken, Pa., 2015and/or ASTM D5035-11(2015), Standard Test Method for Breaking Force andElongation of Textile Fabrics (Strip Method), ASTM International, WestConshohocken, Pa., 2015. Tensile strength of a fabric may be measured inthe machine direction and/or the cross machine direction of the fabricstructure. The tensile strength may be measured and/or determined uponinitial formation of the composition and/or at about 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24month(s) or year(s) or more after initial formation of the compositionand/or after exposure to certain conditions, such as, but not limitedto, real world outdoor conditions (e.g., in California, Arizona and/orTexas), sun exposure, heat exposure, and/or conditions in accordancewith AATCC 169 Option 3. In some embodiments, the acrylic compositionhas a tensile strength that is increased by at least 5%, 10%, 15%, or20% at about 3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or12 months or 5 or 10 years of outdoor exposure) and/or after exposure to880, 1320, or 2200 kJ in accordance with AATCC 169 Option 3 compared toa comparative composition (e.g., a control composition of the sameform). In some embodiments, after exposure to 880, 1320, or 2200 kJ inaccordance with AATCC 169 Option 3, the acrylic composition (e.g., fiberor yarn (e.g., a 10″ yarn sample)) may be wrapped in one layer thicknessaround a 5.5″ polystyrene plaque and tested on tensile tester (e.g., anIntron tensile tester) for tensile strength, and the results may be donein replicate and averaged. In some embodiments, tensile strength may bedetermined with an unpigmented acrylic composition of the presentinvention and/or an unpigmented comparative composition, e.g., bycomparing the compositions and/or one or more properties thereof.

In some embodiments, the tensile strength an acrylic composition of thepresent invention (e.g., a fabric) varies by about 0% or by less thanabout ±50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, or 1% after aperiod of time and/or after exposure to certain conditions compared tothe initial tensile strength of the acrylic composition. In someembodiments, an acrylic composition of the present invention (e.g.,fabric) has a tensile strength that varies by about 0% or by less thanabout ±50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, or 1% at about3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or 12 months or 5or 10 years of outdoor exposure) and/or after exposure to 880, 1320, or2200 kJ in accordance with AATCC 169 Option 3.

In some embodiments, an acrylic composition may be in the form of afiber and/or yarn, such as, e.g., a yarn having a 18/2 Ring Spun CottonCount, and may have a tensile strength in a range of about 2lbs/breaking force to about 4 lbs/breaking force, such as, e.g., 2.3 to3.8 lbs/breaking force, optionally on average. In some embodiments, afiber and/or yarn may have a tensile strength of about 2, 2.1, 2.2, 2.3,2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8,3.9, or 4 lbs/breaking force, optionally on average. In someembodiments, the tensile strength of a fiber and/or yarn may be measuredusing a rate of speed of about 12 inches per minute, optionally using anInstron® system.

In some embodiments, an acrylic composition of the present invention(e.g., fabric) has a break strength and/or flexibility that is increasedby at least 5% (e.g., about 10%, 15%, 20%, 25%, 30%, or more) comparedto a current commercial acrylic composition of the same form (e.g., acurrent commercial acrylic fabric) and/or a control composition of thesame form (e.g., a fabric without a hindered amine light stabilizer).Break strength and/or flexibility may be measured in accordance withASTM D5034-09(2013), Standard Test Method for Breaking Strength andElongation of Textile Fabrics (Grab Test), ASTM International, WestConshohocken, Pa., 2013. Break strength and/or flexibility of a fabricmay be measured in the machine direction and/or the cross machinedirection of the fabric structure. The break strength and/or flexibilitymay be measured and/or determined upon initial formation of thecomposition and/or at about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 month(s) or years(s) or moreafter initial formation of the composition and/or after exposure tocertain conditions, such as, but not limited to, real world outdoorconditions (e.g., in California, Arizona and/or Texas), sun exposure,heat exposure, and/or conditions in accordance with AATCC 169 Option 3.In some embodiments, the acrylic composition has a break strength and/orflexibility that is increased by at least 5%, 10%, 15%, or 20% at about3, 6, 9, or 12 months or 5 or 10 years (e.g., 3, 6, 9, or 12 months or 5or 10 years of outdoor exposure) and/or after exposure to 880, 1320, or2200 kJ in accordance with AATCC 169 Option 3 compared to a comparativecomposition (e.g., a control composition of the same form). In someembodiments, after exposure to 880, 1320, or 2200 kJ in accordance withAATCC 169 Option 3, the acrylic composition (e.g., fiber or yarn (e.g.,a 10″ yarn sample)) may be wrapped in one layer thickness around a 5.5″polystyrene plaque and tested on tensile tester (e.g., an Instrontensile tester) for break strength and/or flexibility, and the resultsmay be done in replicate and averaged. In some embodiments, breakstrength and/or flexibility may be determined with an unpigmentedacrylic composition of the present invention and/or an unpigmentedcomparative composition, e.g., by comparing the compositions and/or oneor more properties thereof.

In some embodiments, the break strength and/or flexibility of an acryliccomposition of the present invention (e.g., a fabric) varies by about 0%or by less than about ±50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%,or 1% after a period of time and/or after exposure to certain conditionscompared to the initial break strength and/or flexibility of the acryliccomposition. In some embodiments, an acrylic composition of the presentinvention (e.g., fabric) has a break strength and/or flexibility thatvaries by about 0% or by less than about ±50%, 45%, 40%, 35%, 30%, 25%,20%, 15%, 10%, 5%, or 1% at about 3, 6, 9, or 12 months or 5 or 10 years(e.g., 3, 6, 9, or 12 months or 5 or 10 years of outdoor exposure)and/or after exposure to 880, 1320, or 2200 kJ in accordance with AATCC169 Option 3.

In some embodiments, an acrylic composition may be in the form of afiber and/or yarn, such as, e.g., a yarn having a 18/2 Ring Spun CottonCount, and may have a break strength in a range of about 2 lbs/breakingforce to about 4 lbs/breaking force, such as, e.g., 2.3 to 3.8lbs/breaking force, optionally on average, and/or an elongation in arange from about 20% to about 30%, optionally on average. In someembodiments, a fiber and/or yarn may have a break strength of about 2,2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5,3.6, 3.7, 3.8, 3.9, or 4 lbs/breaking force, optionally on average,and/or an elongation of about 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%,28%, 29%, or 30%, optionally on average. Break strength and/orelongation may be measured using methods known to those of skill in theart, such as, e.g., using an Uster Tensojet. In some embodiments, breakstrength and/or elongation of a fiber and/or yarn may be measured usinga rate of speed of about 12 inches per minute, optionally using anInstron® system.

In some embodiments, an acrylic composition may be in the form of afiber and the fiber may have a tenacity in a range of about 30 to about50. In some embodiments, the fiber may have a tenacity of about 30, 31,32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49,or 50. Tenacity may be measured using methods known to those of skill inthe art, such as, e.g., in accordance with EN ISO 5079 (ISO 5079:1995“Textile fibres—Determination of breaking force and elongation at breakof individual fibres”), optionally using a Textechno FafegraphHR+Textechno Vibromat ME.

An acrylic composition of the present invention may have reduced or noacrylonitrile polymer degradation compared to a current commercialacrylic composition of the same form (e.g., a current commercial acrylicfabric) and/or a control composition of the same form (e.g., a fabricwithout a hindered amine light stabilizer). In some embodiments,acrylonitrile polymer degradation may be measured and/or determined bymeasuring and/or determining the amount of low molecular weight chainspresent in the acrylic composition after a period of time and/or afterexposure to certain conditions compared to the initial amount of lowmolecular weight chains present in the acrylic composition. In someembodiments, acrylonitrile polymer degradation may be measured and/ordetermined by measuring and/or determining the amount of a moiety,functional group, and/or impurity present in the acrylic compositionafter a period of time and/or after exposure to certain conditionscompared to the initial amount of the moiety, functional group, and/orimpurity present in the acrylic composition. In some embodiments, themoiety, functional group, and/or impurity may be a degradation productresulting from attack on the polymer (e.g., polymer backbone) by oxygenand/or a nucleophilic agent, a degradation product resulting from ahydrolysis and/or oxidation reaction, and/or may be the result and/orproduct of a β-ketonitrile defect in the polymer chain (e.g., oneintroduced during polymerization). In some embodiments, the moiety,functional group, and/or impurity may comprise a double bond. In someembodiments, polymer degradation (e.g., the formation of low molecularweight chains present in the acrylic composition) may be measured and/ordetermined upon initial formation of the composition and at about 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24 month(s) or year(s) or more after initial formation of thecomposition and/or after exposure to certain conditions, such as, butnot limited to, real world outdoor conditions (e.g., in California,Arizona and/or Texas), sun exposure, heat exposure, and/or conditions inaccordance with AATCC 169 Option 3. In some embodiments, improvements inpolymer degradation of an acrylic composition of the present inventioncompared to a comparative composition may be determined by comparing thetensile strength, break strength, and/or flexibility of thecompositions. In some embodiments, polymer degradation may be determinedwith an unpigmented acrylic composition of the present invention and/oran unpigmented comparative composition, e.g., by comparing thecompositions and/or one or more properties thereof. Methods known tothose of skill in the art including, but not limited to,Fourier-transform infrared spectroscopy (FTIR), Gas chromatography-massspectrometry (GCMS), surface techniques, microscopy, and/or molecularweight analysis may be used to determine and/or measure polymerdegradation.

In some embodiments, an acrylic composition of the present (e.g.,fabric) has a thermal stability that is increased by at least 5% (e.g.,about 10%, 15%, 20%, 25%, 30%, or more) compared to a current commercialacrylic composition of the same form (e.g., a current commercial acrylicfabric) and/or a control composition of the same form (e.g., a fabricwithout a hindered amine light stabilizer). The thermal stability may bemeasured and/or determined upon initial formation of the compositionand/or at about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24 month(s) or year(s) or more after initialformation of the composition and/or after exposure to certainconditions, such as, but not limited to, real world outdoor conditions(e.g., in California, Arizona and/or Texas), sun exposure, heatexposure, and/or conditions in accordance with AATCC 169 Option 3. Insome embodiments, the acrylic composition has a thermal stability thatis increased by at least 5%, 10%, 15%, or 20% at about 3, 6, 9, or 12months or 5 or 10 years (e.g., 3, 6, 9, or 12 months or 5 or 10 years ofoutdoor exposure) and/or after exposure to 880, 1320, or 2200 kJ inaccordance with AATCC 169 Option 3 compared to a comparativecomposition. In some embodiments, improvements in thermal stability ofan acrylic composition of the present invention compared to acomparative composition may be determined by comparing the tensilestrength, break strength, and/or flexibility of the compositions. Insome embodiments, thermal stability may be determined with anunpigmented acrylic composition of the present invention and/or anunpigmented comparative composition, e.g., by comparing the compositionsand/or one or more properties thereof.

An acrylic composition of the present invention may have reduced or nophotooxidation compared to a current commercial acrylic composition ofthe same form (e.g., a current commercial acrylic fabric) and/or acontrol composition of the same form (e.g., a fabric without a hinderedamine light stabilizer). In some embodiments, photooxidation may bemeasured and/or determined by measuring and/or determining the amount ofa moiety, functional group, and/or impurity present in the acryliccomposition after a period of time and/or after exposure to certainconditions compared to the initial amount of the moiety and/orfunctional group present in the acrylic composition. In someembodiments, the moiety, functional group, and/or impurity may comprisea double bond. In some embodiments, photooxidation may be measuredand/or determined upon initial formation of the composition and at about1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23, 24 month(s) or year(s) or more after initial formation ofthe composition and/or after exposure to certain conditions, such as,but not limited to, real world outdoor conditions (e.g., in California,Arizona and/or Texas), sun exposure, heat exposure, and/or conditions inaccordance with AATCC 169 Option 3. In some embodiments, improvements inphotooxidation of an acrylic composition of the present inventioncompared to a comparative composition may be determined by comparing thetensile strength, break strength, and/or flexibility of thecompositions. In some embodiments, photooxidation may be determined withan unpigmented acrylic composition of the present invention and/or anunpigmented comparative composition, e.g., by comparing the compositionsand/or one or more properties thereof. Methods known to those of skillin the art including, but not limited to, FTIR, GCMS, surfacetechniques, microscopy, and/or molecular weight analysis may be used todetermine and/or measure photooxidation.

At least two types of degradation may be found in an acrylic composition(e.g., an acrylic fabric) when used in outdoor applications. These formsof degradation can be related to the pigments used for coloration in thesolution dyeing process and/or base polymer degradation. Pigmentselection can be important to achieve the needed color fastness foroutdoor textile end uses. Pigments are often selected and tested inseveral accelerated weathering test methods to indicate performance.Examples of these tests can include SAE J2527 (SAE J2527 “PerformanceBased Standard for Accelerated Exposure of Automotive Exterior MaterialsUsing a Controlled Irradiance Xenon-Arc Apparatus” J2527_200402, Issued:2004 Feb. 11), which is a simulation of Florida weather, and AATCC 169Option 3, which is representative of Arizona conditions. As one of skillin the art will recognize, after the selection of proper pigments, thereare several steps which are needed to prepare the pigments prior toinjection into the polymer stream and subsequent fiber formation tocreate long lasting outdoor products.

Polymer degradation can manifest itself in two ways: strength retentionand discoloration. Strength retention can be measured after acceleratedweathering or outdoor exposure using a common tensile test in both themachine and cross machine direction of the fabric structure. Eventhrough an acrylic composition may lose some tensile strength aftertime, it is still far superior to other commonly used products made fromolefins and/or polyester, which are different in chemical composition.In view of this superiority, often acrylics will last for 5 or moreyears outdoors in a variety of environments. However, some ecru acrylicfibers and/or fabrics may have more degradation compared to pigmentedacrylics since pigmented packages are not incorporated into the polymer.

The second way that polymer degradation can be observed is in thediscoloration of the composition. In hot and high UV conditions, anacrylic composition (e.g., fiber and/or fabric) may turn a shade ofyellow to light brown as the composition is degraded. Test methods suchas, e.g., AATCC 169 Option 3, can be used to observe and/or measure bothstrength retention and polymer discoloration.

When exposed to UV light in the 300 nm-400 nm range, the light (energy)can be absorbed by chromophores, which can create photochemicalreactions in the polymer, resulting in functional groups and/orimpurities in the acrylic composition (e.g., fiber and/or fabric). Thedegree of polymer degradation can depend on the environment the acryliccomposition is exposed to. One common method of color change may happenas a carbon nitrogen triple bond is excited through irradiation of UVenergy. “Color change” as used herein refers to a change in color of anykind, such as, e.g., in lightness, hue, and/or chroma. According toaspects of the present invention, in some embodiments, a hindered aminelight stabilizer may function as a radical scavenger, e.g., using acyclic regeneration of nitrile mechanism. A hindered amine lightstabilizer may interact with a detrimental free radical and may notattract hydrogen present in the acrylonitrile polymer backbone. In someembodiments, a hindered amine light stabilizer may only interact with adetrimental free radical. Oxygen may react within the acrylonitrilepolymer backbone to create hydrogen peroxides which may also degrade theacrylonitrile polymer chain. In some embodiments, a hindered amine lightstabilizer may function to remove or attract hydrogen peroxide and/orprecursors thereof.

Discoloration (e.g., yellowing or browning) of the acrylonitrile polymermay be due to a new chromophore being formed, optionally after a certainnumber double bonds are created in the polymer structure. Alternativelyor in addition, discoloration and/or polymer degradation may be seenafter chain scissoring within the acrylonitrile polymer. The degree ofdiscoloration may be influenced by the comonomer optionally present inthe acrylic composition. Comonomers such as, but not limited to,methacrylate, methyl methacrylate and vinyl acetate, contain ester(s)which can be prone to degradation. In some embodiments, an acrylonitrilepolymer comprises one or more co-monomer(s) that contain an ester.

Any suitable method may be used to determine and/or measure the improvedand/or positive effects of adding and/or incorporating a hindered aminelight stabilizer into an acrylic composition of the present invention.In some embodiments, GC-MS and/or FTIR analysis may be used to confirmimproved stability before and/or after weathering and/or after exposureto certain conditions. In some embodiments, an acrylic composition maybe tested in accordance with AATCC 169 Option 3 for color change inlight pigmented shades and/or unpigmented fibers. In some embodiments,tensile strength testing of an acrylic composition may be performedafter exposure to conditions in accordance with AATCC Option 3 comparedto a control composition exposed to the same conditions.

As one of ordinary skill in the art will recognize, acrylic fiber can beproduced via several different production methods. Any suitableproduction method may be used in a method of the present invention. Anoverview of an example acrylic process is provided in FIG. 2. Ingeneral, a method for producing an acrylic fiber can be divided into thefollowing steps: polymerization, production of a spinning solution,fiber spinning, and optional post-treatments. As shown in FIG. 2, amethod of the present invention may comprise polymerizing (e.g., by freeradical polymerization) an acrylonitrile monomer and optionally acomonomer (block 100). The comonomer may be used to provide specificphysical properties of the acrylonitrile polymer. A spinning solution(e.g., a dope) may be prepared that includes the polymerizedacrylonitrile polymer (block 120), and before, during, and/or afterpreparation of the spinning solution a hindered amine light stabilizer(HALS) may be added to the acrylonitrile polymer (block 125). In someembodiments, prior to fiber spinning, the acrylonitrile polymer may besolubilized into a dope using a suitable solvent and a HALS may be addedto the dope. The spinning solution may then be spun (e.g., extruded)using a spinning process to provide one or more acrylic fiber(s) (block140). As one of ordinary skill in the art will recognize a spinningprocess (e.g., a wet or dry spinning process) can involve passing thespinning solution through a spinneret to spin (e.g., extrude) an acrylicfiber. The acrylic fiber(s) may then be treated and/or go through one ormore post-processing steps. In some embodiments, the acrylic fiber(s)may be treated (block 160), such as, e.g., contacting the acrylicfiber(s) with a dye, pigment, finish, and/or coating solution,optionally during the spinning step (block 140). The acrylic fiber(s)may be annealed (block 180). In some embodiments, the acrylic fibers maybe tow baled (block 188). Alternatively, the acrylic fibers may berecrimped (block 185) and/or cut and baled (block 190).

“Dope” as used herein refers to a homogeneous solution comprising anacrylonitrile polymer (e.g., a polyacrylonitrile homopolymer and/orcopolymer), one or more (e.g., 1, 2, 3, 4, or more) solvent(s), andoptionally one or more (e.g., 1, 2, 3, 4, or more) additive(s). Examplesolvents that may be used in a dope include, but are not limited to,dimethylformamide, dimethylacetamide, and/or dimethyl sulfoxide. In someembodiments, the solvent is a polar organic solvent. In someembodiments, a dope may have a composition as provided in Table 2.

TABLE 2 Example dope compositions. Solvent present in the Dope %Acrylonitrile Polymer in the Dope Dimethylformamide 28%-32%Dimethylacetamide 22%-27% Aqueous Sodium thiocyanate 10%-15% AqueousZinc Chloride  8%-12% Dimethyl sulfoxide 20%-25% Nitric Acid  8%-12%

Once the dope has been created, optionally one or more additive(s)and/or pigment(s) may be injected into the dope and/or a dope stream,and may be mixed prior to the fiber spinning process. A spinneret may beused to form an acrylic fiber as the dope (e.g., viscous dope) movesthrough one or more hole(s) of the spinneret. In the case of wetspinning, an acrylic fiber may begin to form in a coagulation bath,which may contain both water and a solvent (e.g., an organic solvent).Gelation of the acrylic fiber occurs as the solvent present in theacrylic fiber begins to move from the acrylic fiber. An example wetspinning process is shown in FIG. 3. In some embodiments, a hinderedamine light stabilizer may be added during and/or after dope preparationand/or prior to the polymer solution reaching the metering pumps asshown in FIG. 3. In the case of dry spinning, fiber formation occursthrough evaporation of the solvent present in the acrylic fiber as thedope exits the spinneret in a heated spinning tube. An example dryspinning process is shown in FIG. 4. In some embodiments, a hinderedamine light stabilizer may be present in the polymer solution and/oradded into the polymer solution prior to drying as shown in FIG. 4.Subsequent processes can involve washing, stretching and/or drying of atow band under specific conditions to create the desired fiberproperties for the end-use application. The resultant product may be,but is not limited to, cut staple fiber, tow, or multifilament yarndepending on the desired finished good.

In some embodiments, a method of the present invention may comprise oneor more post-treatments. Any suitable post-treatment may be used in amethod of the present invention. In some embodiments, an acrylic fiberis contacted with a finishing and/or coating treatment known to those ofskill in the art, such as, e.g., contacted with a fluorinated compoundand/or polymer.

According to some embodiments of the present invention, a method ofpreparing an acrylic fiber is provided, the method comprising: adding ahindered amine light stabilizer to an acrylonitrile polymer to provide astabilized acrylic composition; and forming an acrylic fiber from thestabilized acrylic composition, thereby preparing the acrylic fiber. Insome embodiments, forming the acrylic fiber from the stabilized acryliccomposition comprises spinning, extruding, and/or the like thestabilized acrylic composition to form the acrylic fiber.

In some embodiments, a hindered amine light stabilizer may be selectedbased on basicity of the hindered amine light stabilizer (e.g., one withlow basicity), migration of the hindered amine light stabilizer in anacrylic composition (e.g., one that provides low migration), durabilityof the hindered amine light stabilizer in an acrylic composition (e.g.,one that provides high durability), and/or heat stability of thehindered amine light stabilizer in an acrylic composition (e.g., onethat provides high and/or long term heat stability). As describedherein, example hindered amine light stabilizers include, but are notlimited to, Tinuvin® 622, Tinuvin® 123, Tinuvin® 111, Tinuvin® 371,Chimassorb® 2020, and/or Cyasorb® 3529.

In some embodiments, adding a hindered amine light stabilizer to theacrylonitrile polymer comprises adding the hindered amine lightstabilizer prior to, during, and/or after a solubilization step and/or afiber spinning step. Referring to FIG. 2, a hindered amine lightstabilizer may be added after a polymerization step and prior to,during, and/or after dope preparation, and/or prior to and/or duringfiber spinning. In some embodiments, a hindered amine light stabilizeris added to the acrylonitrile polymer prior to, during, and/or after asolubilization step, optionally with, at the same time as, orsequentially with one or more additive(s) and/or pigment(s). A pigmentand/or additive may be added to an acrylonitrile polymer prior to,during and/or after the adding of the hindered amine light stabilizer tothe acrylonitrile polymer. In some embodiments, a composition comprisinga hindered amine light stabilizer and one or more additive(s) and/orpigment(s) is added to the acrylonitrile polymer. In some embodiments, apigment and/or additive is separately added to the acrylonitrilepolymer, optionally at the same time as a hindered amine lightstabilizer.

In some embodiments, a hindered amine light stabilizer is added to anacrylonitrile polymer once a dope has been created, and may be injectedinto the dope and/or a dope stream optionally with one or moreadditive(s) and/or pigment(s). The dope containing the hindered aminelight stabilizer may be mixed and then may go through a fiber spinningstep. The method may comprise a wet spinning or dry spinning fibermanufacturing process.

One or more (e.g., 1, 2, 3, 4, 5, or more) hindered amine lightstabilizer(s) as described herein may be added to the acrylonitrilepolymer at any suitable concentration. In some embodiments, one or morehindered amine light stabilizer(s) may be added to the acrylonitrilepolymer in any suitable form (e.g., dry form (e.g., a powder) and/or inliquid form (e.g., a solution)). In some embodiments, a hindered aminelight stabilizer may be added to the acrylonitrile polymer at aconcentration greater than or equal to the desired concentration for thehindered amine light stabilizer in the acrylic composition. For example,a hindered amine light stabilizer may be present in an acrylic fiber inan amount in a range from about 0.01% to about 10% by weight of anacrylic fiber.

In some embodiments, a hindered amine light stabilizer (HALS) may beadded at a concentration in a range of about 0.01%, 1%, or 5% to about10%, 20%, or 30% by weight of the acrylic composition (e.g., the acrylicfiber). In some embodiments, a hindered amine light stabilizer may beadded at a concentration of about 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%,4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%,19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30% by weightof the acrylic composition (e.g., the acrylic fiber). In someembodiments, a hindered amine light stabilizer is added to a dope and/orsolvent, e.g., at a concentration in a range of about 0.01%, 1%, or 5%to about 10%, 20%, or 30% by weight of the acrylic composition (e.g.,the acrylic fiber). A hindered amine light stabilizer used in a methodand/or acrylic composition of the present invention may be compatiblewith, dissolved in, and/or soluble in a dope and/or solvent used in amethod of the present invention. The solvent may be and/or the dope maycomprise a polar solvent.

In some embodiments, a hindered amine light stabilizer (e.g., in powderform) may be prepared in a manner similar to a pigment for a solutiondyeing process. This may involve use of a dope solution and mixingsystem. Once premixing has occurred, the solution may be milled to agiven particle size and/or evenness of the material. In someembodiments, an acrylonitrile polymer may be mixed with a solutioncomprising a hindered amine light stabilizer and optionally an additiveand/or pigment, which may aid in dispersing the solution duringinjection. In some embodiments, a hindered amine light stabilizer may beadded directly into a solution (e.g., a solvent) without the presence ofan acrylonitrile polymer, and this may involve mixing to provideadequate solubility. In some embodiments, a solution comprising ahindered amine light stabilizer may be filtered and/or the viscosity ofthe solution may be determined. A solution comprising a hindered aminelight stabilizer may be stored in a container or reservoir (e.g., atote), optionally with a circulation system or proper mixing apparatus.

A method of the present invention may further comprise forming a yarn,thread, and/or fabric from the acrylic fiber. Any suitable method forforming the yarn, thread, and/or fabric from the acrylic fiber may beused. In some embodiments, a method of the present invention comprisesweaving an acrylic fiber and/or yarn into an acrylic fabric. Anysuitable weave may be used, including, but not limited to, a plainweave, twill weave, leno weave, dobby weave, jacquard weave, and/orsatin weave.

A method of the present invention may provide and/or produce an acrylicfiber and/or fabric comprising the same having one more improvedproperties, such as, but not limited to, those described herein (e.g.,reduced polymer degradation and/or reduced discoloration) compared to acomparative fiber and/or fabric comprising the comparative fiber. Insome embodiments, a method of the present invention may produce anacrylic fiber and/or fabric for outdoor end use and/or that is suitablefor outdoor use, optionally wherein the acrylic fiber and/or fabric hasimproved properties, such as, e.g., reduced polymer degradation and/orreduced discoloration.

In some embodiments, a hindered amine light stabilizer is added to anacrylonitrile polymer after polymerization of the acrylonitrile polymerand prior to fiber spinning. The hindered amine light stabilizer may beadded (e.g., injected) into a dope (e.g., at a concentration of about0.01% to about 30% by weight of the dope), optionally in a mannersimilar to a pigment (e.g., by using a metering pump) to provide astabilized acrylic composition. The hindered amine light stabilizer maybe in a solution, such as, e.g., a solution comprising a solvent and thehindered amine light stabilizer. In some embodiments, the hindered aminelight stabilizer is added to a portion of a dope, which may then beadded to the remaining portion of the dope and/or a dope fiber stream.After being added to (e.g., injected into) the dope and/or a dope fiberstream, the stabilized acrylic composition may be mixed (e.g., with along mixing screw), which may disperse the hindered amine lightstabilizer within the stabilized acrylic composition prior to spinning.The stabilized acrylic composition may then be extruded (e.g., through aspinneret) and phase separated into a gel in a wet spinning bath (i.e.,a coagulation bath) comprising water and solvent (e.g., in a givenratio). Better fine fiber structures may be provided in a coagulationbath with a higher solvent to water ratio and reduced temperatures.These properties can slow the phase change as the fiber is being formed.An example coagulation bath may comprise about 60% DMAc and about 40%water and may be at a temperature of about 45° C. with a spin dopetemperature of less than 120° C. In some embodiments, a spinneret mayhave about 10,000 to about 60,000 holes. Fiber spinning may likely occurat about 3 meters/min to about 10 meters/min.

In some embodiments, addition of a hindered amine light stabilizer maybe completed prior to injection into a dope stream. The hindered aminelight stabilizer may be diluted in a solvent, which may aid in providinga constant and/or consistent feeding through a metering pump. Dispersionand/or runnability issues may occur if the concentration of the hinderedamine light stabilizer is too high and/or viscous. These issues maymanifest as clogging of the spinneret holes.

Referring now to FIGS. 5A and 5B, a hindered amine light stabilizer maybe added to an acrylonitrile polymer to provide a stabilized acryliccomposition prior to fiber spinning via injection in a solution dyeingprocess (similar to pigment addition). As shown in FIG. 5A, a tote ormaster line can transport a hindered amine light stabilizer (e.g., asolution containing the hindered amine light stabilizer) to theinjection site prior to a mixing screw. As shown in FIG. 5B, thehindered amine light stabilizer and optionally one or more pigments maythen be dosed into the polymer stream from the tote or master line, thenmixed and filtered for consistency. In some embodiments, the hinderedamine light stabilizer may be selectively added to given batches of anacrylonitrile polymer.

Referring now to FIG. 6, prior to and/or during fiber spinning, ahindered amine light stabilizer may be added to an acrylonitrile polymerat one or more steps in a process of preparing a dope to provide astabilized acrylic composition. In some embodiments, the HALS may beadded to the acrylonitrile polymer at the same time as the solventand/or may be present in the solvent. In some embodiments, the HALS maybe added to the acrylonitrile polymer after the solvent is added, suchas, e.g., during mixing of the dope and/or prior to, during, and/orafter heating and/or filtering of the dope. In some embodiments, theHALS may be added to the dope prior to and/or during fiber spinning. Thedope may comprise the polymer, one or more solvent(s), and optionallyone or more additive(s) (e.g., antioxidant(s)) and/or pigment(s)).

The present invention is explained in greater detail in the followingnon-limiting examples.

EXAMPLES Example 1

Strength retention and color stability were studied in several trials atlab scale and production scale using specific HALS formulations ofTinuvin® 123 (i.e., Additive 2) or Tinuvin® 622 (i.e., Additive 1) withecru or pigmented fibers. An acrylonitrile polymer was prepared having acomposition comprising 94% of poly(acrylonitrile-co-vinyl acetate), 5.9%of vinyl acetate, and 0.1% sodium styrene sulfonate. Subsequently, 0% toabout 1.5% of a HALS additive and 0% to about 2% of a pigment, each byweight of the acrylic fiber (i.e., on weight of the fiber), were addedto the dope stream comprising the acrylonitrile polymer (similar to theprocess as shown in FIG. 5B) and a wet spinning process was used toprovide the acrylic fibers. The acrylic fiber was a 2 denier fiber witha 45 mm staple length. The acrylic fibers were prepared into a 18/2 ringspun cotton count with 12.25 turns per inch in the singles yarn and 12.4turns per inch the ply.

These results demonstrated an improvement in performance for the sampleswith a HALS when tested according to AATCC 169 Option 3 with theparameters shown in Table 3. The AATCC 169 Option 3 method is ofinterest as this method yields conditions that are expected to manifestthe degradation of the acrylic material. This xenon arc method uses aborosilicate/borosilicate filter with 0.35 W/m2 irradiance at 340 nm,77° C. black panel temperature with continuous light exposure.Measurements for either tensile strength or color changes are done atincrements of 880, 1,320, 2,200 kJs of UV exposure.

TABLE 3 Parameters used for AATCC 169 Option 3 (i.e., AATCC 169-3).AATCC 169 Option 3 Wavelength (Measured) 340 nm Irradiance (Measured)0.35 W/m2 Lamp Type Xenon Arc Filter System (outer/inner)Borosilicate/Borosilicate nm exposure limits 200-800 nm Black Panel 77+/− 3 C. Conditioning Water Temp 40 C. Wet bulb depression ~20 C. Wetbulb ~35 C. Dry bulb ~55 C. Humidity 27 +/− 3% RH water spray none Lightcycle length continuous Dark cycle length none Exposure and observationobservations made at 880 kJ, 1320 cycles kJ and 2200 kJ (0.79 kJ/hr)

For strength retention testing, a 18/2 ring spun acrylic yarn waswrapped in one layer thickness around a 5.5″ polystyrene plaque. Aftereach xenon arc increment was completed, a 10″ yarn sample was tested onan Instron tensile tester for grams/force breaking strength andelongation. A 10″ sample was chosen to ensure at least half of themeasured sample was exposed in the xenon arc test. This process wascompleted with 10 replicate breaks and then averaged to obtain theresult.

In the case of color change evaluations, a knitted sock was created andmounted to the same 5.5″ polystyrene card, but a paper mask withperforated tabs was placed over the samples. The perforated sections canbe removed to expose the sample to different increments in the testmethod. Once the desired increments were completed, samples wereevaluated using a spectrophotometer or rated per AATCC gray scale forcolor change.

Base polymer yellowing evaluations were completed in accordance withAATCC 169 Option 3 for ecru and pigmented fibers. In each case,improvements were clearly seen for fibers including a HALS compared tothose without. After 2,200 kJ exposure in AATCC 169 Option 3, thesamples containing a HALS showed significant improvement in base polymerstability of the fiber compared to those that did not contain a HALS(i.e., control fibers that were not doped with a HALS). It can be notedthat ecru fiber incurred a larger color change and strength degradationthan pigmented fiber. While not wishing to be bound to any particulartheory, this is believed to be due to stabilization and absorptionproperties of the pigments used in pigmented fiber that are absent inecru fiber.

Lab Scale Results:

Table 4 provides the results for the yarn strength retention aftertesting the samples (i.e., control and HALS samples) after exposure toxenon arc according to AATCC 169-3. FIG. 7 is a graph of ecru sampleyarn break strength retention after AATCC 169 Option 3 testing, and FIG.8 is a graph of ecru sample yarn elongation retention after AATCC 169Option 3 testing. FIG. 9 is a graph of lab scale pigmented sample yarnbreak strength retention after AATCC 169 Option 3 testing, and FIG. 10is a graph of lab scale pigmented sample yarn elongation retention afterAATCC 169 Option 3 testing.

TABLE 4 Lab Scale AATCC 169-3 (WOM) Yarn Strength Retention. 880 13202200 Original kJ/m² kJ/m² kJ/m² Ecru (Control) Break Strength (lbs)3.517 2.506 2.349 1.423 Elongation (%) 27.12 19.35 17.65 6.791 Ecru0.75% Additive 1 Break Strength (lbs) 2.92 2.564 2.416 1.62 Elongation(%) 25.39 20.98 19.63 9.52 Ecru 1% Additive 1 Break Strength (lbs) 3.2353.024 3.038 2.749 Elongation (%) 26.7 24.08 24.01 21.13 Ecru 1.5%Additive 1 Break Strength (lbs) 3.349 3.168 3.159 2.996 Elongation (%)26.86 25.41 25.35 23.77 Ecru 0.75% Additive 2 Break Strength (lbs) 3.5473.047 2.703 1.761 Elongation (%) 28.15 23.52 21.05 11.56 Ecru 1%Additive 2 Break Strength (lbs) 3.386 2.783 2.519 1.718 Elongation (%)27.63 23.22 20.73 12.2 Ecru 1.5% Additive 2 Break Strength (lbs) 3.2523.007 2.94 2.024 Elongation (%) 27.48 25.44 23.14 16.03 Pigmented 0.75%Additive 1 Break Strength (lbs) 3.349 3.528 3.15 3.039 Elongation (%)26.47 26.03 23.19 22.49 Pigmented 1% Additive 1 Break Strength (lbs)3.084 3.13 3.05 2.857 Elongation (%) 26.44 25.46 24.97 21.95 Pigmented1.5% Additive 1 Break Strength (lbs) 2.812 2.953 2.765 2.271 Elongation(%) 24.87 24.44 23.78 20.36 Pigmented 0.75% Additive 2 Break Strength(lbs) 3.171 3.06 2.797 1.911 Elongation (%) 25.96 24.56 23.47 14.89Pigmented 1% Additive 2 Break Strength (lbs) 3.44 3.205 3.044 1.664Elongation (%) 27.49 25.69 25.04 16.54 Pigmented 1.5% Additive 2 BreakStrength (lbs) 3.443 3.399 3.522 2.421 Elongation (%) 28.5 26.45 26.5419.38 Pigmented (Control) Break Strength (lbs) 3.695 3.216 2.829 1.847Elongation (%) 28.26 19.15 17.08 9.89

Table 5 shows the CIE Delta E values for ecru knitted sock samples aftertesting according to AATCC 169-3, and Table 6 shows the CIE Delta Evalues for pigmented knitted sock samples after testing according toAATCC 169-3. The spectrophotometric measurements were made using aDatacolor 650 with a Daylight source. FIG. 11 is a graph of the labscale ecru sample fabric CIE Delta E values after AATCC 169 Option 3testing, and FIG. 12 a graph of the lab scale pigmented sample fabricCIE Delta E values after AATCC 169 Option 3 testing.

TABLE 5 Lab scale CIE Delta E values for ecru samples after AATCC 169-3testing. Sample 880 kJ 1320 kJ 2200 kJ Control Ecru 13.64 17.72 20.690.75% Additive 1 Ecru 6.11 7.75 11.3 1% Additive 1 Ecru 1.82 2.37 3.791.5% Additive 1 Ecru 1.3 1.1 1.36 0.75% Additive 2 Ecru 2.98 4.22 6.571% Additive 2 Ecru 2.39 3.2 5.45 1.5% Additive 2 Ecru 1.74 2.27 4.25

TABLE 6 Lab scale CIE Delta E values for pigmented samples after AATCC169-3 testing. Sample 880 kJ 1320 kJ 2200 kJ Control Pigmented 2.18 34.54 0.75% Additive 1 Pigmented 1.02 1.41 1.46 1% Additive 1 Pigmented0.95 1.12 1.45 1.5% Additive 1 Pigmented 0.57 0.74 1.01 0.75% Additive 2Pigmented 0.27 0.21 0.73 1% Additive 2 Pigmented 0.22 0.24 0.42 1.5%Additive 2 Pigmented 0.31 0.36 0.21

Table 7 shows the CIE Delta E values for ecru knitted sock samples afterreal world weathering by outdoor exposure in South Carolina, and Table 8shows the CIE Delta E values for pigmented knitted sock samples afterreal world weathering by outdoor exposure in South Carolina. Thespectrophotometric measurements were made using a Datacolor 650 with aDaylight source. Specimens were mounted at a 45-degree angle using anAtlas weathering rack facing due south in South Carolina. FIG. 13 is agraph of the lab scale ecru sample fabric CIE Delta E values afteroutdoor exposure in South Carolina.

TABLE 7 Lab scale ecru sample fabric CIE Delta E values after outdoorexposure in South Carolina. Sample 3 Mon 6 Mon 9 Mon 12 Mon Control Ecru7.66 10.48 10.68 14.31 0.75% Additive 1 Ecru 1.8 3.9 4.5 7.07 1%Additive 1 Ecru 2.24 1.62 2.6 3.66 1.5% Additive 1 Ecru 2.69 1.64 2.32.8 0.75% Additive 2 Ecru 2.38 2.78 3.92 5.16 1% Additive 2 Ecru 2.362.14 3.29 3.83 1.5% Additive 2 Ecru 2.35 2.78 3.57 4.15

TABLE 8 Lab scale pigmented sample fabric CIE Delta E values afteroutdoor exposure in South Carolina. Sample 3 Mon 6 Mon 9 Mon 12 MonControl Pigmented 0.9 1.43 0.99 1.73 0.75% Additive 1 Pigmented 1.111.65 1.55 1.94 1% Additive 1 Pigmented 1.01 1.58 1.41 1.93 1.5% Additive1 Pigmented 0.92 1.37 1.32 1.6 0.75% Additive 2 Pigmented 0.63 0.66 0.740.72 1% Additive 2 Pigmented 0.87 0.7 0.91 0.99 1.5% Additive 2Pigmented 0.69 0.64 0.98 0.72

Table 9 shows the CIE Delta E values for ecru knitted sock samples afterreal world weathering by outdoor exposure in Arizona, and Table 10 showsthe CIE Delta E values for pigmented knitted sock samples after realworld weathering by outdoor exposure in Arizona. The spectrophotometricmeasurements were made using a Datacolor 650 with a Daylight source.Specimens were mounted at a 45-degree angle using an Atlas weatheringrack facing due south in Arizona. FIG. 14 is a graph of the lab scaleecru sample fabric CIE Delta E values after outdoor exposure in Arizona.As can be seen, e.g., in Table 9, a cycle of base polymer discolorationcan be observed in acrylic products in hot and high UV areas wherediscoloration can increase over time (e.g., at time point 1), thenexhibit a reduction (e.g., at time point 2, which has a lower CIE DeltaE value than at time point 1), only to increase again (e.g., at timepoint 3, which has a higher CIE Delta E value than at time point 2).While not wishing to be bound to any particular theory, this phenomenonmay be due to a reduction in acrylonitrile polymer molecular weightreduction, e.g., as areas of newly formed double bonds are alteredand/or some chromophores are broken.

TABLE 9 Lab scale ecru sample fabric CIE Delta E values after outdoorexposure in Arizona. Sample 3 Mon 6 Mon 9 Mon 12 Mon Control Ecru 18.6812.61 18.11 17.84 0.75% Additive 1 Ecru 7.86 4.61 9.61 10.25 1% Additive1 Ecru 4.09 2.13 5.24 4.53 1.5% Additive 1 Ecru 3.72 1.61 3.17 3.730.75% Additive 2 Ecru 8.63 4.27 8.21 8.6 1% Additive 2 Ecru 6.22 3.188.43 6.62 1.5% Additive 2 Ecru 7.14 3.64 7.49 7.36

TABLE 10 Lab scale pigmented sample fabric CIE Delta E values afteroutdoor exposure in Arizona. Sample 3 Mon 6 Mon 9 Mon 12 Mon ControlPigmented 1.79 0.48 1.89 1.91 0.75% Additive 1 Pigmented 0.89 0.88 1.141.53 1% Additive 1 Pigmented 0.79 0.94 1.07 1.17 1.5% Additive 1Pigmented 0.65 0.74 0.75 0.92 0.75% Additive 2 Pigmented 0.87 0.51 0.570.75 1% Additive 2 Pigmented 1 0.54 1.23 0.73 1.5% Additive 2 Pigmented0.48 0.51 0.93 0.4

Production Scale:

For the production scale testing, a 2.2 dtex×48 mm acrylic staple fiberwas made by wet spinning PAN using dimethylacetamide and 1% of eachadditive. Target properties of key importance include dtex, tensilestrength, and elongation. Table 11 reflects ecru production data asmeasured using a Textechno Fafegraph HR+Textechno Vibromat ME with thetest in accordance with EN ISO 5079.

TABLE 11 Ecru staple fiber production data. Fiber with Fiber with LimitsAdditive 1 Additive 2 Dtex 1.95-2.45 2.4 1.99 Tenacity (cN/TEX) 30minimum 41 38 Elongation (%) 25-40 36 31

Fiber made using Additive 1 or Additive 2 was ring spun into 18/2 cottoncount yarn. Again, key measurements include yarn strength and elongationproperties, which were measured using an Uster Tensojet. Data wasrecorded at three different audit times (e.g., beginning, middle, andend) in the yarn spinning merge for both Additive 1 and Additive 2(Table 12).

TABLE 12 Production scale yarn strength and yarn elongation. YarnStrength (cN/TEX) Yarn Elongation % Ecru Control 27.92 20.94 Additive1-Sample A 27.50 21.68 Additive 1-Sample B 28.09 21.72 Additive 1-SampleC 27.40 21.89 Additive 2-Sample A 27.60 21.76 Additive 2-Sample B 27.5121.99 Additive 2-Sample C 27.78 22.03

The yarns were then woven into two different common textileconstructions for evaluation in fabric. All values achieved wereacceptable for commercial textiles. Each textile was finished with afluorocarbon-based water and oil repellent.

TABLE 13 Plain weave 100% acrylic fabric with 75 ends × 35 picks.Control Additive 1 Additive 2 ASTM D3776-96: 8.7 8.8 8.6 Weight (ouncesper square yard) ASTM D5034-95: 320 326 331 Break lbs. (machinedirection) ASTM D5034-95: 199 213 199 Break lbs. (cross direction) ASTMD2261-96: 17 18 18 Tear lbs. (machine direction) ASTM D2261-96: 13 13 13Tear lbs. (cross direction) AATCC 22-2001: 100 100 100 Spray waterresistance AATCC118-1997: 6 6 6 Oil resistance

TABLE 14 Plain weave 100% acrylic fabric with 68 ends × picks. ControlAdditive 1 Additive 2 ASTM D3776-96: 7.7 7.6 7.7 Weight (ounces persquare yard) ASTM D5034-95: 348 330 334 Break lbs. (machine direction)ASTM D5034-95: 165 164 172 Break lbs. (cross direction) ASTM D2261-96:20 18 19 Tear lbs. (machine direction) ASTM D2261-96: 15 16 15 Tear lbs.(cross direction) AATCC 22-2001: 100 100 100 Spray water resistanceAATCC118-1997: 5 5 5 Oil resistance

In accordance with AATCC 169-3, evaluations for color change werecompleted after exposure of 75 ends×35 picks woven and finished fabricsamples as described above (Table 15) and after exposure of 68 ends×30picks woven and finished fabric samples as described above (Table 16).The spectrophotometric measurements were made using a Datacolor 650 witha Daylight source. FIG. 15 is a graph of the production scale ecrusample plain weave fabric 75 epi×35 ppi CIE Delta E values after AATCC169 Option 3 testing, and FIG. 16 is a graph of the production scaleecru sample plain weave fabric 68 epi×30 ppi CIE Delta E values afterAATCC 169 Option 3 testing.

TABLE 15 Production scale CIE Delta E values for ecru plain weave 75 epi× 35 ppi fabric samples after AATCC 169-3 testing. Sample 880 kJ 1320 Kj2200 kJ Control Ecru Plain Weave 75 epi × 35 ppi 11.12 13.75 18 Additive1 Ecru Plain Weave 75 epi × 35 ppi 4.02 4.96 6.83 Additive 2 Ecru PlainWeave 75 epi × 35 ppi 4.86 5.46 6.88

TABLE 16 Production scale CIE Delta E values for ecru plain weave 68 epi× 30 ppi fabric samples after AATCC 169-3 testing. Sample 880 kJ 1320 Kj2200 kJ Control Ecru Plain Weave 68 epi × 30 ppi 10.13 12.55 17.03Additive 1 Ecru Plain Weave 68 epi × 30 ppi 4.92 5.92 7.81 Additive 2Ecru Plain Weave 68 epi × 30 ppi 4.19 4.77 5.96

Evaluations for color change using real world weathering in SouthCarolina were completed after exposure of 75 ends×35 picks woven andfinished fabric samples as described above (Table 17) and after exposureof 68 ends×30 picks woven and finished fabric samples as described above(Table 18). The spectrophotometric measurements were made using aDatacolor 650 with a Daylight source. Specimens were mounted at a45-degree angle using an Atlas weathering rack facing due south in SouthCarolina. FIG. 17 is a graph of the production scale ecru sample plainweave fabric 75 epi×35 ppi CIE Delta E values after outdoor exposure inSouth Carolina, and FIG. 18 is a graph of the production scale ecrusample plain weave fabric 68 epi×30 ppi CIE Delta E values after outdoorexposure in South Carolina.

TABLE 17 Production scale CIE Delta E values for ecru plain weave 75 epi× 35 ppi fabric samples after outdoor exposure in South Carolina. Sample3 Mon 6 Mon 9 Mon Control Ecru Plain Weave 75 epi × 35 ppi 8.23 8.159.67 Additive 1 Ecru Plain Weave 75 epi × 35 ppi 4.58 6.87 6.92 Additive2 Ecru Plain Weave 75 epi × 35 ppi 4.88 6.84 4.49

TABLE 18 Production scale CIE Delta E values for ecru plain weave 68 epi× 30 ppi fabric samples after outdoor exposure in South Carolina. Sample3 Mon 6 Mon 9 Mon Control Ecru Plain Weave 68 epi × 30 ppi 7.01 8.618.78 Additive 1 Ecru Plain Weave 68 epi × 30 ppi 3.59 4.95 5.09 Additive2 Ecru Plain Weave 68 epi × 30 ppi 4.32 5.29 5.43

Evaluations for color change using real world weathering in Arizona werecompleted after exposure of 75 ends×35 picks woven and finished fabricsamples as described above (Table 19) and after exposure of 68 ends×30picks woven and finished fabric samples as described above (Table 20).The spectrophotometric measurements were made using a Datacolor 650 witha Daylight source. Specimens were mounted at a 45-degree angle using anAtlas weathering rack facing due south in Arizona. FIG. 19 is a graph ofthe production scale ecru sample plain weave fabric 75 epi×35 ppi CIEDelta E values after outdoor exposure in Arizona, and FIG. 20 is a graphof the production scale ecru sample plain weave fabric 68 epi×30 ppi CIEDelta E values after outdoor exposure in Arizona.

TABLE 19 Production scale CIE Delta E values for ecru plain weave 75 epi× 35 ppi fabric samples after outdoor exposure in Arizona. Sample 3 Mon6 Mon 9 Mon Control Ecru Plain Weave 75 epi × 35 ppi 11.6 22.03 16.35Additive 1 Ecru Plain Weave 75 epi × 35 ppi 5.52 13.99 9.18 Additive 2Ecru Plain Weave 75 epi × 35 ppi 5.37 10.96 6.39

TABLE 20 Production scale CIE Delta E values for ecru plain weave 68 epi× 30 ppi fabric samples after outdoor exposure in Arizona. Sample 3 Mon6 Mon 9 Mon Control Ecru Plain Weave 68 epi × 30 ppi 11.12 20.24 14.87Additive 1 Ecru Plain Weave 68 epi × 30 ppi 5.65 12.97 8.05 Additive 2Ecru Plain Weave 68 epi × 30 ppi 5.85 11.31 6.66

The break strength and elongation of the production scale 2.2 dtex×48 mmacrylic staple fiber was also tested and the results are provided inTable 21. FIG. 21 is a graph of the production scale ecru sample yarnbreak strength retention after AATCC 169 Option 3 testing, and FIG. 22is a graph of the production scale ecru sample yarn elongation retentionafter AATCC 169 Option 3 testing.

TABLE 21 Production scale yarn strength retention results. Original 880kJ/m² 1320 kJ/m² 2200 kJ/m² Ecru (Control) Break Strength (lbs) 3.7152.523 2.327 1.293 Elongation (%) 26 17.89 15.35 4.814 Additive 1 EcruBreak Strength (lbs) 3.443 3.038 2.828 1.991 Elongation (%) 26.17 22.7621.66 15.75 Additive 2 Ecru Break Strength (lbs) 3.507 3.257 3.297 2.224Elongation (%) 26.13 24.13 24.05 16.95

Example 2

Heat stability was examined using specific HALS formulations of Tinuvin®123 (i.e., Additive 2) or Tinuvin® 622 (i.e., Additive 1) in ecruacrylic fibers that were woven in a fabric having a plain weave with 75epi×35 ppi or 68 epi×30 ppi as described in Example 1. The fabricsamples were exposed to a temperature of 85° C. for 7 days in a forcedair oven in accordance with LP-463LB-13-01, May 4, 2006, “Heat Aging ofTrim Materials”.

Delta E values were then measured for the heated samples and comparedagainst non-heated samples of the same type. Tables 22 and 23 providethe CIE Delta E values for the fabrics. Additive 1 had a positive impacton heat stability during this testing and the heated fabric samples hadless yellowing compared to the control samples.

TABLE 22 CIE Delta E values for Ecru Plain Weave 75 epi × 35 ppi FabricSamples. CIE Delta E (Heated Sample Compared to Initial) Control EcruPlain Weave 75 epi × 35 ppi 1.05 Additive 1 Ecru Plain Weave 75 epi × 35ppi 0.82 Additive 2 Ecru Plain Weave 75 epi × 35 ppi 2.27

TABLE 23 CIE Delta E values for Ecru Plain Weave 68 epi × 30 ppi FabricSamples. CIE Delta E (Heated Sample Compared to Initial) Control EcruPlain Weave 68 epi × 30 ppi 1.09 Additive 1 Ecru Plain Weave 68 epi × 30ppi 0.46 Additive 2 Ecru Plain Weave 68 epi × 30 ppi 1.75

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although exemplary embodiments of thisinvention have been described, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. The invention is defined by the following claims, withequivalents of the claims to be included therein.

1.-40. (canceled)
 41. An acrylic fiber comprising: an acrylonitrilepolymer having acrylonitrile units present in an amount of at least 85%by weight of the acrylonitrile polymer; and a hindered amine lightstabilizer; wherein the hindered amine light stabilizer has a pKa from 4to 7 and has a water solubility at 20° C. of about 2% w/w or less;wherein the hindered amine light stabilizer is within the acrylic fiberin an amount of about 0.5% to about 10% by weight of the acrylic fiberand is distributed throughout the polymer matrix of the acrylonitrilepolymer; wherein the acrylonitrile polymer is selected from the groupconsisting of polyacrylonitrile (PAN), poly(acrylonitrile-co-vinylacetate) (P(AN-VA)), poly(acrylonitrile-co-methyl acrylate) (P(AN-MA)),poly(acrylonitrile-co-vinyl chloride) (PAN-VC),poly(acrylonitrile-co-vinylidene chloride, poly(acrylonitrile-co-methylmethacrylate), and any combination thereof; and wherein the hinderedamine light stabilizer has a structure represented by Formula (I),Formula (II), Formula (III), or Formula (IV):

wherein: each X is independently selected from the group consisting ofC1-C20 alkyl and C1-C20 alkenyl; L, in each instance, is absent or isindependently selected from the group consisting of C1-C20 alkyl andC1-C20 alkenyl; each R¹ is independently selected from the groupconsisting of C1-C20 alkyl, C1-C20 alkenyl, —O(C1-C20 alkyl), and—O(C1-C20 alkenyl); each R² is independently selected from the groupconsisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl; each R³ isindependently selected from the group consisting of hydrogen, C1-C20alkyl, and C1-C20 alkenyl; and n is an integer selected from 1 to 50.42. (canceled)
 43. The acrylic fiber of claim 41, wherein theacrylonitrile polymer comprises one or more comonomer units selectedfrom the group consisting of vinyl acetate, vinyl chloride, vinylidenechloride, styrene, methyl methacrylate, vinyl acetate, methyl acrylate,sodium styrene sulfonate, sodium methallyl sulfonate, sodium sulfophenylmethallyl, ether, itaconic acid, and any combination thereof. 44.-45.(canceled)
 46. The acrylic fiber of claim 41, wherein the hindered aminelight stabilizer has a pKa from 4 to 6.5.
 47. The acrylic fiber of claim41, wherein the hindered amine light stabilizer has a molecular weightfrom about 500 g/mol to about 4500 g/mol. 48.-51. (canceled)
 52. Theacrylic fiber of claim 41, wherein the hindered amine light stabilizerhas a structure represented by Formula (I), and wherein: X is a C1-C20alkyl; L is absent; each R¹ is independently selected from the groupconsisting of —O(C1-C20 alkyl) and —O(C1-C20 alkenyl); and each R² isindependently selected from the group consisting of hydrogen, C1-C20alkyl, and C1-C20 alkenyl.
 53. The acrylic fiber of claim 41, whereinthe hindered amine light stabilizer has a structure represented byFormula (II), and wherein: each X is independently selected from thegroup consisting of C1-C10 alkyl and C1-C10 alkenyl; each R² isindependently selected from the group consisting of hydrogen, C1-C20alkyl, and C1-C20 alkenyl; and n is an integer selected from 1 to 50.54. The acrylic fiber of claim 41, wherein the acrylic fiber comprisestwo or more different hindered amine light stabilizers.
 55. The acrylicfiber of claim 41, wherein the acrylic fiber is in staple, filament, ortow form.
 56. The acrylic fiber of claim 41, wherein the acrylic fiberis unpigmented.
 57. The acrylic fiber of claim 41, further comprising apigment.
 58. The acrylic fiber of claim 41, wherein the acrylic fiber issolution-dyed.
 59. The acrylic fiber of claim 41, wherein the acrylicfiber, when measured devoid of a pigment, has a Gray scale value of 5after exposure to about 100 kJ of light.
 60. The acrylic fiber of claim41, wherein the acrylic fiber is in the form of a yarn and the yarn hasa tensile strength that is increased by at least 20% compared to acontrol yarn after exposure of each to 2200 kJ in accordance with AATCC169 Option
 3. 61. The acrylic fiber of claim 41, wherein the acrylicfiber is in the form of a yarn and the yarn has a break strength and/orflexibility that changes by less than about 45% after exposure to 2200kJ in accordance with AATCC 169 Option
 3. 62. The acrylic fiber of claim41, wherein the acrylic fiber is in the form of a yarn and the yarn isin the form of a fabric, and wherein the fabric has reduced or nodiscoloration compared to a control fabric after exposure of each to2200 kJ in accordance with AATCC 169 Option
 3. 63. The acrylic fiber ofclaim 41, wherein the acrylic fiber is in the form of a yarn and theyarn is in the form of a fabric, and wherein the fabric has a CIE DeltaE value of less than about 5 after exposure to 2200 kJ in accordancewith AATCC 169 Option
 3. 64. The acrylic fiber of claim 41, wherein theacrylic fiber is in the form of a yarn and the yarn is in the form of afabric, and wherein the fabric has a CIE Delta E value after exposure to880 kJ in accordance with AATCC 169 Option 3 that varies by less thanabout ±60% compared to a CIE Delta E value after exposure to 2200 kJ inaccordance with AATCC 169 Option
 3. 65. A method of preparing an acrylicfiber of claim 41, the method comprising: adding a hindered amine lightstabilizer to an acrylonitrile polymer to provide a stabilized acryliccomposition; and forming an acrylic fiber from the stabilized acryliccomposition, thereby preparing the acrylic fiber.
 66. The method ofclaim 65, wherein adding the hindered amine light stabilizer to theacrylonitrile polymer comprises adding the hindered amine lightstabilizer prior to and/or during a solubilization step and/or a fiberspinning step. 67.-68. (canceled)
 69. The method of claim 65, furthercomprising adding a pigment and/or additive to the acrylonitrilepolymer.
 70. An article comprising an acrylic fiber of claim
 41. 71. Anacrylic composition comprising: an acrylonitrile polymer havingacrylonitrile units present in an amount of at least 85% by weight ofthe acrylonitrile polymer; and a hindered amine light stabilizer in anamount of about 0.5% to about 10% by weight of the acrylic composition;wherein the acrylonitrile polymer comprises one or more comonomer unitsselected from the group consisting of vinyl acetate, styrene, methylmethacrylate, vinyl acetate, methyl acrylate, sodium styrene sulfonate,sodium methallyl sulfonate, sodium sulfophenyl methallyl, ether,itaconic acid, and any combination thereof; wherein the hindered aminelight stabilizer has a pKa from 4 to 7; wherein the acrylic composition,when formed into an acrylic fiber devoid of a pigment, has a Gray scalevalue of 5 after exposure to about 100 kJ of light; and wherein thehindered amine light stabilizer has a structure represented by Formula(I), Formula (II), Formula (III), or Formula (IV):

wherein: each X is independently selected from the group consisting ofC1-C20 alkyl and C1-C20 alkenyl; L, in each instance, is absent or isindependently selected from the group consisting of C1-C20 alkyl andC1-C20 alkenyl; each R¹ is independently selected from the groupconsisting of C1-C20 alkyl, C1-C20 alkenyl, —O(C1-C20 alkyl), and—O(C1-C20 alkenyl); each R² is independently selected from the groupconsisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl; each R³ isindependently selected from the group consisting of hydrogen, C1-C20alkyl, and C1-C20 alkenyl; and n is an integer selected from 1 to 50.72. An acrylic fiber comprising: an acrylonitrile polymer havingacrylonitrile units present in an amount of at least 85% by weight ofthe acrylonitrile polymer; and a hindered amine light stabilizer in anamount of about 0.5% to about 10% by weight of the acrylic fiber;wherein the hindered amine light stabilizer has a pKa from 4 to 7;wherein the acrylonitrile polymer is selected from the group consistingof polyacrylonitrile (PAN), poly(acrylonitrile-co-vinyl acetate)(P(AN-VA)), poly(acrylonitrile-co-methyl acrylate) (P(AN-MA)),poly(acrylonitrile-co-vinyl chloride) (PAN-VC),poly(acrylonitrile-co-vinylidene chloride, poly(acrylonitrile-co-methylmethacrylate), and any combination thereof; wherein the hindered aminelight stabilizer is within the acrylic fiber and is distributedthroughout a cross-section of the acrylic fiber; and wherein thehindered amine light stabilizer has a structure represented by Formula(I), Formula (II), Formula (III), or Formula (IV):

wherein: each X is independently selected from the group consisting ofC1-C20 alkyl and C1-C20 alkenyl; L, in each instance, is absent or isindependently selected from the group consisting of C1-C20 alkyl andC1-C20 alkenyl; each R¹ is independently selected from the groupconsisting of C1-C20 alkyl, C1-C20 alkenyl, —O(C1-C20 alkyl), and—O(C1-C20 alkenyl); each R² is independently selected from the groupconsisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl; each R³ isindependently selected from the group consisting of hydrogen, C1-C20alkyl, and C1-C20 alkenyl; and n is an integer selected from 1 to 50.73.-74. (canceled)
 75. The acrylic fiber of claim 72, wherein theacrylic fiber, when measured devoid of a pigment, has a Gray scale valueof 5 after exposure to about 100 kJ of light.
 76. (canceled)
 77. Theacrylic fiber of claim 41, wherein the hindered amine light stabilizeris distributed substantially uniformly throughout the acrylic fiber. 78.The acrylic fiber of claim 41, wherein the hindered amine lightstabilizer consists of one hindered amine light stabilizer having a pKafrom 4 to 7 and water solubility at 20° C. of about 2% w/w or less. 79.(canceled)
 80. The acrylic composition of claim 71, wherein the hinderedamine light stabilizer has a structure represented by Formula (I), andwherein: X is a C1-C20 alkyl; L is absent; each R¹ is independentlyselected from the group consisting of —O(C1-C20 alkyl) and —O(C1-C20alkenyl); and each R² is independently selected from the groupconsisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl.
 81. Theacrylic composition of claim 71, wherein the hindered amine lightstabilizer has a structure represented by Formula (II), and wherein:each X is independently selected from the group consisting of C1-C10alkyl and C1-C10 alkenyl; each R² is independently selected from thegroup consisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl; and n isan integer selected from 1 to
 50. 82. The acrylic fiber of claim 72,wherein the hindered amine light stabilizer has a structure representedby Formula (I), and wherein: X is a C1-C20 alkyl; L is absent; each R¹is independently selected from the group consisting of —O(C1-C20 alkyl)and —O(C1-C20 alkenyl); and each R² is independently selected from thegroup consisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl.
 83. Theacrylic fiber of claim 72, wherein the hindered amine light stabilizerhas a structure represented by Formula (II), and wherein: each X isindependently selected from the group consisting of C1-C10 alkyl andC1-C10 alkenyl; each R² is independently selected from the groupconsisting of hydrogen, C1-C20 alkyl, and C1-C20 alkenyl; and n is aninteger selected from 1 to 50.